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Treatments for Traumatic Brain Injury With Emphasis on Transcranial Near-Infrared Laser Phototherapy

Larry D Morries, Paolo Cassano, Theodore A Henderson, - This article was published in Neuropsychiatric Disease and Treatment, 20 August 2015 (Publication)
This exceptional research indicated prefered wavelenghts and dosages for treating patients with traumatic brain injuries. The found some surprising results.
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Abstract:

Traumatic brain injury (TBI) is a growing health concern affecting civilians and military personnel. In this review, treatments for the chronic TBI patient are discussed, including pharmaceuticals, nutraceuticals, cognitive therapy, and hyperbaric oxygen therapy. All available literature suggests a marginal benefit with prolonged treatment courses. An emerging modality of treatment is near-infrared (NIR) light, which has benefit in animal models of stroke, spinal cord injury, optic nerve injury, and TBI, and in human trials for stroke and TBI. The extant literature is confounded by variable degrees of efficacy and a bewildering array of treatment parameters. Some data indicate that diodes emitting low-level NIR energy often have failed to demonstrate therapeutic efficacy, perhaps due to failing to deliver sufficient radiant energy to the necessary depth. As part of this review, we present a retrospective case series using high-power NIR laser phototherapy with a Class IV laser to treat TBI. We demonstrate greater clinical efficacy with higher fluence, in contrast to the bimodal model of efficacy previously proposed. In ten patients with chronic TBI (average time since injury 9.3 years) given ten treatments over the course of 2 months using a high-power NIR laser (13.2 W/0.89 cm2 at 810 nm or 9 W/0.89 cm2 at 810 nm and 980 nm), symptoms of headache, sleep disturbance, cognition, mood dysregulation, anxiety, and irritability improved. Symptoms were monitored by depression scales and a novel patient diary system specifically designed for this study. NIR light in the power range of 10-15 W at 810 nm and 980 nm can safely and effectively treat chronic symptoms of TBI. The clinical benefit and effects of infrared phototherapy on mitochondrial function and secondary molecular events are discussed in the context of adequate radiant energy penetration. Keywords: infrared, traumatic brain injury, TBI, transcranial infrared light therapy, transcranial laser therapy 

INTRODUCTION

Traumatic brain injury (TBI) has recently moved into the limelight due to the recognition of its impact on professional athletes and military personnel. Yet, TBI is neither a new problem nor limited to those two populations. The Centers for Disease Control and Prevention estimated that 1.5 million Americans sustained TBI annually in 2000.1 As of 2006, the estimates had risen to 1.7 million brain injuries annually.2,3 Undoubtedly, these point prevalence proportions will increase as military personnel return home,4 and the problem of repeated mild TBI (mTBI) becomes more recognized in sports.5 Current estimates of the prevalence of TBI among veterans range from 9.6%6 to 20%,7 with an estimated total of more than 300,000 cases of TBI among military personnel since 2000.4 The current estimates of the combined number of sportsrelated concussions and brain injuries in the US are 1.6-3.8 million annually.8-10 TBI results in a wide spectrum of neurological, psychiatric, cognitive, and emotional consequences. In part, the variation is related to the severity of the injury (mild, moderate, severe TBI), which is stratified based on Glasgow Coma score, periods of unconsciousness, and degrees of amnesia. Furthermore, the diversity of sequalae can be related to the areas of the brain that are injured, the severity of the injury (highly variable within the classification of “mild” and “moderate”), and the evolution of the injury over time due to neuroinflammatory processes.11,12 Additional mechanisms thought to underlie the damage of TBI include decreased mitochondrial function, calcium and magnesium dysregulation, excitotoxicity, disruption of neural networks, free radicalinduced damage, excessive nitric oxide, ischemia, and damage to the blood-brain barrier. Together, these can contribute to a progression of the damage over time. Patients with TBI can experience headache, visual disturbances, dizziness, cognitive impairment, loss of  executive skills, memory impairment, fatigue, impulsivity, impaired judgment, emotional outbursts, anxiety, and depression.3,13-23 The situation can be further clouded by secondary and/ or comorbid posttraumatic stress disorder (PTSD), depression, and anxiety,17-25 which can have symptoms that overlap with those described above and appear to be increasingly likely with repetitive concussive or subconcussive brain injury.5,24,26

TREATMENTS FOR TBI

Pharmacological treatments Pharmacological treatment largely targets the neuropsychiatric sequalae of TBI, rather than providing any means of healing or repairing injury. In general, pharmacological treatment is focused on the modulation of major neurotransmitter systems – dopaminergic, serotonergic, noradrenergic, acetylcholinergic, and glutaminergic.20 Disruption of the major neurotransmitter pathways may result from direct injury or excitotoxicity and other cytotoxic mechanisms. The treatment of depression secondary to TBI is often approached with serotonin reuptake inhibitors. Several studies have examined the benefit of sertraline in post- TBI depression.27-29 Other serotonin reuptake inhibitors also have been examined. Tricyclic antidepressants appear to have some use in the treatment of post-TBI depression, although cautious dose titration is required. Patients with TBI are at greater vulnerability to sedation and cholinergic side effects of confusion and memory impairment. With serotonergic agents other than sertraline, cognitive effects also have been reported.30 Similarly, lithium may be a less desirable agent in this  population due to sedation and cognitive impairment. Patients with TBI may respond at lower doses and lower blood levels than expected. Modulation of the dopaminergic system may improve alertness, attention, and cognitive processing speed. The stimulants are most commonly used for this purpose. Methylphenidate facilitates the release of dopamine and slows its reuptake. Dextroamphetamine strongly inhibits reuptake of dopamine, slows down the breakdown of dopamine by monoamine oxidase, and somewhat increases the release of dopamine. These subtle differences are sometimes imperceptible to the patient, but at other times, a patient will do best on one or the other stimulant. Increasing dopamine in the reticular activating system leads to enhanced arousal. Increasing dopamine within the frontal cortex and the striatum leads to enhanced processing speed and attention. Some evidence suggests that the stimulants may enhance neuronal recovery after injury.31-33 There are numerous potential side effects with stimulants, including abnormal heart rhythms, decreased seizure threshold, and death, but these severe side effects are extremely rare. The most common side effects with stimulants are decreased appetite, stomach upset, and headache. These are most severe at the beginning of treatment and improve over time for most patients. Insomnia is another common side effect, which may be more frequent in those with a TBI. Amantadine and bromocriptine may also increase dopamine. Studies of these agents have shown reduced abulia, anergia, and anhedonia in those with TBI.34,35 Amantadine may cause confusion, hallucinations, and hypotension. Small studies have suggested some benefits of bromocriptine in cognitive function.36,37 Arousal-enhancing agents also have found a use in the treatment of the neurocognitive sequalae of TBI. Modafinil is the oldest form of these medications, and armodafinil is an isomer of modafinil with longer activity and less side effects. These medications help to increase alertness and wakefulness. The precise mechanism of action of odafinil is unclear. It appears to increase histamine in parts of the brain involved in controlling the sleep-wake cycle; however, knock-out mice that lack histamine receptors still show increased wakefulness with modafinil.38,39 The picture is also murky  for modafinil’s effect on orexins, which are wakefulness molecules in the hypothalamus.40 Modafinil has been shown to weakly bind to the dopamine transporter – like the stimulants,41 and dopamine transporter knock-out mice show no response to modafinil.42 A number of research studies have examined the benefit of these agents in fatigue associated with multiple sclerosis, TBI, cancer, and other conditions. Cognitive and memory impairments after TBI may reflect disruption of cholinergic function. The impact of anticholinergic agents on cognitive function of those with TBI supports this contention. Donepezil is the safest and most widely used of the cholinesterase inhibitors. Several easonably large studies have shown improved memory and cognitive function.43-45 Donepezil has benefits in memory and cognition even several years after injury.45,46  Anticonvulsants are often prescribed initially after a TBI due to heightened risk for seizures. Post-TBI mania or mood lability may respond well to anticonvulsants, such as carbamazepine or sodium valproate. They are also often used to treat aggression after TBI. The anticonvulsant agent, topiramate, has been shown to adversely affect cognitive function in the TBI patients.47 While insomnia is a significant issue for patients with TBI, affecting between 15% and 84% (mean of 40%),3,13,19,21,23,48,49 little has been published on the treatment of this aspect of TBI. Benzodiazepines may  be effective but carry a risk of disinhibition. Kemp et al48 found that commonly used sleep aid, melatonin, was not effective. Antidepressants, including serotonin reuptake inhibitors and tricyclic antidepressants, are not effective in resolving insomnia in this population.49 No single agent has emerged as a good solution for this symptom. Cognitive rehabilitation Cognitive rehabilitation now takes many forms and is often individualized to the particular needs of the patients. Protocols have been devised to remediate cognitive difficulties often encountered in those with TBI, such as impaired concentration, executive dysfunction,  inattention, visual disturbances, memory dysfunction, and impaired language function. They range from simple strategies (using a planner to aid memory and organization) to specific protocols targeting particular cognitive functions (eg, short-term memory) that can be monitored with sequential neuropsychological testing. These interventions have been extensively reviewed elsewhere.50,51 Comprehensive programs which include psychotherapy and social skills components have been shown to have greater efficacy.50,52,53 Overall, reports of benefits have been mixed.54,55 Behavioral therapies Behavioral remediation strategies to eliminate problematic  behaviors following TBI have met with mixed success, most often in terms of the poor generalization of specific skills to the outside world. Behavioral deficits that create difficulties for those with TBI and their families include poor hygiene, decline in tidying/cleaning habits, social withdrawal, reduced social comprehension, impaired memory, and poor organization. Behavioral excesses that create difficulties for those with TBI and their families include aggression, sleep disruption, and perseverations. These have been reviewed elsewhere.56 Nutritional supplements Nutritional supplements, herbs, and nootropics have been utilized for many years and are increasingly popular among the patient populations. There remains little clinical research on many of these agents, perhaps reflecting a lack of funding more than a lack of efficacy. Acetyl-l-carnitine is an ester of l-carnitine and is thought to protect brain cells after injury when glucose metabolic pathways are compromised. During this period, acetyll- carnitine supports alternative ketogenic pathways for metabolism.57 It is also believed to enhance cholinergic function. While there are several clinical studies on patients with Alzheimer’s disease and preclinical data on animal models of TBI, the clinical literature on TBI remains sparse. Ginkgo biloba is a natural product of the tree by the same name. It has been shown to improve membrane fluidity and increase resistance to free-radical damage. It provides some subtle benefits to cognitive function in clinical studies of stroke, dementia, aging, and hypoxia damage.58 It has not been systematically studied in TBI but is used extensively in clinic, often in combination with meclofenoxate which is an avid scavenger of free radicals.59 S-Adenosylmethionine (SAMe) is a nutritional supplement which improves cell membrane fluidity and promotes the production of glutathione, an antioxidant. The benefit of SAMe has been assessed in a single clinical study of TBI.60 Patients receiving SAMe had a 77% improvement in clinical scores of post-concussive symptoms. Citicholine provides a source of choline which can cross the bloodbrain barrier. It has been used extensively in Europe and Japan as a treatment for TBI, stroke, and dementia. However, two large US studies failed to demonstrate significant benefit.61,62 Piracetam and the related oxiracetam and phenylpiracetam have shown some promise as nootropic agents. In one double-blind, placebo-controlled study, piracetam improved several symptoms of postconcussive syndrome, including headache and vertigo.63 More recent clinical studies have shown marginal benefit.64 Huperzine-A, an extract of Japanese club moss, is a natural acetylcholinesterase inhibitor. It may serve as a natural alternative to donepezil, rivastigmine, or galantamine. Galantamine warrants special mention as it appears to also modulate nicotinic  eceptors and appears to have more persistent benefit in the treatment of Alzheimer’s disease. It appears to modulate neuroimmune responses, in addition to its effects on acetylcholinesterase.65 Cerebrolysin is a polypeptide that purportedly mimics the actions of neurotrophic factors.66,67 Studies have shown that it can reduce beta amyloid and phosphorylated tau protein accumulation. It may promote neurogenesis, synapse formation, and functional recovery.66 In animal models of acute TBI, cerebrolysin-treated rats had more surviving neurons in the area of impact and showed greater functional recovery.67 In a clinical trial of acute TBI, patients were recruited within 24 hours of injury and treated for 3 months with daily intravenous infusion of cerebrolysin. At 3 months, those receiving cerebrolysin performed significantly better on the Cognitive Abilities Screening Instrument.68 It remains unclear if cerebrolysin provides long-term nootropic benefit. The elevation of free radicals in TBI suggests that antioxidants should be beneficial. Clinical trials of pharmacological antioxidants over the past 30 years have not yielded a useful agent in acute TBI.69 Agents, such as tirilazad70 and polyethylene glycol- onjugated superoxide dismutase, have failed to show benefit in acute TBI. Omega-3 fatty acids may enhance brain repair and recovery, based on animal and clinical studies.71 Similarly, vitamin D may offer neuroprotective and restorative benefits72 in the acute TBI setting. In chronic TBI, vitamin D and omega-3 fatty acids may work synergistically, as they both may reduce neuroinflammation, apoptosis, and oxidative stress.73 Other nutritional supplements have been recommended, but prolonged therapy is necessary to possibly see benefits in TBI. A 6-month trial of ginkgo, vinpocetine, acetyl-lcarnitine, huperzine, alpha-lipoic acid, n-acetyl-cysteine, multivitamins, and over 5 g of omega-3 fatty acids daily yielded improved performance in cognitive testing and increased perfusion (function) in single-photon emission computed tomography (SPECT) scan.74 Long-term use of dietary flavanols may improve cognition in mTBI.75 Transcranial magnetic stimulation Transcranial magnetic stimulation (TMS) has shown some promise in animal models of TBI.76 However, a Cochrane review of the clinical application of TMS for depression noted no difference between repetitive TMS (rTMS) and sham rTMS using the Beck Depression Inventory (BDI) or the Hamilton Depression Rating Scale, except during the initial 2-week period.77 The application of TMS in the post-TBI patients is limited by the risk of seizure induction.78 Hyperbaric oxygen Hyperbaric oxygen treatment has been explored as a treatment for TBI.79-91 Hyperbaric oxygen therapy is neither a benign treatment, given the concerns of oxygen toxicity,79 nor a clear treatment in that the placebo condition of moderate hyperbaric room air also effectively improves cognitive function.80,81 The most carefully performed study compared a group in a cross-over design with an interval of both null treatment and hyperbaric oxygen at 100% oxygen and 1.5 atm.82 The study described improvement in many of the symptoms associated with persistent TBI including headache, tinnitus, vision disturbance, memory dysfunction, and impaired cognitive function. Cognitive testing also showed improvement in attention, information processing speed, and a battery of cognitive tests. In an uncontrolled case series of 16 subjects, Harch et al83 demonstrated that an abbreviated series of hyperbaric treatments using 100% oxygen at 1.5 atm could mitigate subjective symptoms of TBI (eg, headache, sleep disruption, irritability), improve cognitive testing scores, and improve cortical function based on SPECT imaging.83 A study of a higher dose (2.4 atm) did not reveal any significant benefit of hyperbaric oxygen therapy compared to a sham-control group treated with 1.3 atm,84 and this result has been extended and confirmed by a related group.85 However, this may reflect an inverse dose- esponse curve, rather than an absence of benefit, in that the low-dose sham group demonstrated significant changes in cognitive testing and symptom frequency.86 Hyperbaric oxygen remains a controversial area in both acute TBI86-89 and chronic TBI.82,83,85,86,90,91 Physical exercise High-energy activities and exercise programs completed through a health club facility or comprehensive rehabilitation program should focus on the same parameters of an age-adjusted and diagnosis-specific program for aerobic conditioning – flexibility, stabilization, and strength. Though it appears safe and is an accepted intervention for TBI, there is a need for further welldesigned studies.92 Exercise was a part of a 6-month study of lifestyle changes described above which yielded improved function based on cognitive testing and perfusion SPECT scans.74

A NEW TREATMENT FOR TBI

Unfortunately, little has been found to reverse the damage of TBI or repetitive concussion which is the root cause of residual cognitive and psychological impairment following TBI.20,93 One potential avenue of treatment for TBI is infrared light, which has shown promising data in a number of applications. Near-infrared (NIR) light has been investigated for its ability to modulate intracellular mechanisms related to healing. The application of NIR light by low-power laser or by light-emitting diode (LED) is also known as laser phototherapy94 or near-infrared photobiomodulation.92 NIR irradiation can facilitate wound healing,95,96 promote muscle repair,95 and stimulate angiogenesis.95,96 NIR phototherapy has been studied and applied clinically in a wide array of ailments, including skin ulcers,97 osteoarthritis,98 peripheral nerve injury,95,96 low back pain,99 myocardial infarction,100 and stem cell induction.101 The finding that NIR light passes relatively efficiently through bone has spurred interest in its application to treating disorders of the brain. Over the past decade, transcranial near-infrared light therapy (NILT)102 has been studied in animal models to understand its ability to repair damaged or dysfunctional brain tissue resulting from stroke and TBI. The first published study of NILT for TBI in humans described two cases of chronic mTBI with significant disability.103 Each patient was treated with an LED device delivering low-level low-level light therapy (LLLT) in the red and NIR range for 6-10 minutes per area daily for several months. Both patients had marked neuropsychological improvement after a minimum of 7-9 months of LLLT treatment. The precise mechanisms underlying photobiomodulation and its therapeutic benefits are not fully understood. The purported effects of NIR are illustrated in Figure 1. Light in the wavelength range of 600-1,200 nm has significant photobiomodulation capability.104 Current data most strongly support that absorption of NIR photons by cytochrome c oxidase in the mitochondrial respiratory chain is the key initiating event in photobiomodulation.95,96,104,105 This induces an increase in cytochrome c oxidase activity which in turn increases adenosine triphosphate (ATP) production. Such an increase in ATP in wounded or underperfused cells may be sufficient to activate cells in areas of injury or metabolic derangement.106 Data from numerous tissue culture and animal studies point to the importance of several secondary molecular and cellular events. For example, NIR photonic energy can modulate reactive oxygen species,95,96,102 activate mitochondrial DNA replication,95,96 increase early-response genes,95 increase growth factor expression, induce cell proliferation, and alter nitric oxide levels.95,96,102 These mechanisms are more fully described in the companion paper.105 When examined in the specific model of neural tissue injury, NIR phototherapy can lead to demonstrable neural repair and recovery. For example, LLLT of a power density of 0.9-36 J/cm2 applied at 24 hours poststroke in a rodent model yielded a 32% reduction in neurological deficits, as well as histochemical evidence of neuron proliferation and migration.106-108 LLLT had similar benefits in a rodent model of TBI.96,109-111 Interestingly, these cellular changes evolved over a period of days after light exposure and persisted for considerably longer than the interval of actual NIR exposure. These findings are consistent with a progressive regeneration cascade set in motion by the NIR light exposure. NILT in stroke NILT, predominately in the form of LLLT, has been investigated in laboratory models of stroke. LLLT applied in a single dose to an ischemic stroke model appeared to induce expression of the growth factor transforming growth factor – beta 1 and suppress the production of peroxynitrite.112 In a rat model of middle cerebral artery occlusion, LLLT at a dose of 0.5-7.5 mW/ cm2 using continuous wavelength light at 808 nm was administered at 24 hours after the acute stroke.108,113 This single application was estimated to deliver 1.8 J/cm2 in total to the cortex surface and resulted in demonstrable neurological improvement. Functional changes were not manifested until approximately 2 weeks after the single treatment. While there was no significant change in the size of the stroke lesion, histochemical evidence of neurogenesis and migrating neurons108 indicate that a cascade of secondary processes was initiated by NILT. A rabbit model of stroke utilizing injection of a blood clot embolus also demonstrated benefit from LLLT.102,114,115 Herein, 808 nm light was applied with an LED delivering 7.5 mW/cm2 and an estimated 0.9-2.6 J/cm2 to the cortical surface. Cortical ATP levels were increased, indicative of increased mitochondrial activity.114 Significant behavioral recovery was also noted; however, neither ATP increased nor neurological function changed at doses less than 0.3-0.7 J/cm2.114,115 At higher doses of 0.9-15 J/cm2, neurological improvement was seen.114,115 The clinical trials of NILT in acute stroke, the Neuro- Thera Effectiveness and Safety Trials 1, 2, and 3 (NEST- 1,-2, -3), were conducted between 2006 and 2009. The Phase II clinical trial (NEST-1) involved 120 patients in a double-blind, placebo- ontrolled study of the effects of NILT within 24 hours of ischemic stroke.116,117 Approximately 60% of the patients experienced clinical benefit, and the safety profile was very good. Thus, NEST-2, a Phase III clinical trial, was undertaken in 2007. A total of 660 patients were enrolled.118 Somewhat surprisingly, the study did not demonstrate statistical clinical improvement using a different outcome measure.119 Post hoc analysis revealed that a portion of the patients who were moderately affected and/or had strokes limited to the cerebral cortex did realize clinically and statistically significant improvement.102 The NEST-3 trial was halted midpoint when it failed to demonstrate statistical benefit on futility analysis.120 A key factor in the interpretation of the results of NEST-3 is that, different from NEST-1, all types of stroke were included as opposed to just cortical strokes. Continuous laser light has a limited depth of penetration (#1 cm into brain tissue) which likely prevents an effect on deeper brain matter. Therefore, the lack of significant benefits from NIR phototherapy in NEST-3 could be related to the fact that ischemic penumbra was not reached by the light (Luis DeTaboada, personal communication, January 2015). While pulsed NIR was not used in the NEST-3 study, it is estimated that pulsed NIR could penetrate up to 3 cm in depth from the cortical surface, therefore possibly extending the therapeutic target to deeper strokes (Luis DeTaboada, personal communication, January 2015). Figure 1 Hypothesized mechanism of action of NiR light therapy. Notes: NiR light (600-980 nm) penetrates tissue to variable depths depending on wavelength, the tissue involved, coherence, and time. A fraction of the photonic energy reaches the mitochondria and is absorbed by cytochrome c oxidase. This activates increased ATP production, increases production of ROS and RNS, and possibly increases NO. Downstream events include increased early-response genes (c-fos and c-jun) and activation of NF-?B, which in turn induces increased transcription of gene products leading to synaptogenesis, neurogenesis, and increased production of inflammatory mediators and growth factors. Abbreviations: NiR, near-infrared; ATP, adenosine triphosphate; ROS, reactive oxygen species; RNS, reactive nitrogen species; NO, nitric oxide; NF-?B, nuclear factor kappa B. NILT in TBi Oron et al109 conducted the first animal studies of NILT for TBI. They found that a single application of NIR light at 808 nm from a 200 mW emitter at 4 hours post-injury resulted in a significant reduction in lesion size by 5 days.109 To date, several groups have studied NILT in animal models, and this material has previously been reviewed.95,121-123 Single applications of 800-810 nm NIR light within 4 hours of injury have been shown to improve neurological function significantly.110,124-126 The same dose of NIR light at 6 hours was less effective125 and at 8 hours had no appreciable benefit.125 NIR photonic energy at other wavelengths was less effective. Wu et al110 examined red light (670 nm) at 4 hours and found a similar improvement in neurological function; however, 730 nm and 980 nm had no neurological benefit. Similar data for lesion volume have been reported. A single dose of 800-810 nm NIR light (fluence of 36 J/cm2) yielded an approximate 50% reduction in the volume of the lesion at 3-4 weeks110,111,124-126 and a possible reduction in the initial spread of neurological injury, based on the marked reduction in lesion volume found at 5 days post-injury.109 Repeated NIR phototherapy treatments appear to have some benefit, but the frequency and number of treatments are critical factors. While a single NIR light application had benefit, daily applications for 3 days yielded much greater neurological benefit126,127 with smaller lesion size,126 fewer degenerating neurons,126 more proliferating cells,126 and greater levels of brain-derived neurotrophic factor (BDNF)127 compared to a single treatment in a mouse model. In contrast, daily treatment for 7 days128 or 14 days126 showed no difference from controls. NIR energy densities in the range of 0.9-36 J/cm2 resulted in significant biochemical and behavioral changes.109-111,124-127 Pulsing of NIR light appears to yield a greater neurological response but only within certain parameters. Pulsing at 10 Hz yielded greater neurological improvement and a significant reduction in lesion size compared to either continuous-wave or pulsed NIR at 100 Hz.111 In the mouse model of moderate TBI, NILT (800-810 nm) improved learning and memory (Morris water maze performance),128 as well as behaviors associated with depression and anxiety (immobility during tail suspension).111,124 The finding that NILT brought about a smaller lesion in the rodent model of TBI compared to untreated mice suggests that decreased apoptosis, reduced spreading lesion penumbra, and/or neurogenesis are induced by NILT. Indeed, NILT can decrease BAX expression, a pro-apoptosis gene,129 increase expression of BCL-2, an anti-apoptosis gene,129 increase nerve growth factor,95 increase BDNF,127 decrease inflammatory markers,130 and decrease numbers of degenerating neurons.126 Together, these mechanisms may reduce the enlargement of the initial lesion during the first day following the lesion.109 Moreover, increased BDNF and nerve growth factor may contribute to synaptogenesis as shown by increased levels of synapsin-1,127 and neurogenesis, as shown by increased numbers of proliferating cells.127 In a double-blind study in healthy volunteers, NILT was beneficial – compared to sham – in memory and attention.131 In this study, the authors shed only one application of NIR light to the right forehead, targeting the right frontal pole of the cerebral cortex (Brodmann’s area 9 and 10). The device was a Class IV laser CG-5000 (Cell Gen Therapeutics, Dallas, TX, USA), and the parameters were as follows: wavelength 1,064 nm, irradiance 250 mW/cm2, fluence 60 J/cm2, and time 4 minutes per site (two sites).131 The subjects who received the NIR treatment had better attention after 2 weeks, measured by the psychomotor vigilance test. They also had better delayed visual memory at the Delayed Match-to-Sample test. This is the only published controlled trial assessing the impact of NILT on cognition; however, other reports have shown the therapeutic effects of NILT in small numbers of TBI patients. In a two-case report in TBI patients,103 NILT (870 nm) improved sustained attention, memory, and executive functions. Both patients were treated with an instrument with three separate LED cluster heads. The parameters used for the treatment were the following: NIR wavelength 870 nm and 633 nm (red light), irradiance 2.2-25.8 mW/cm2, fluence 13.3 J/cm2, and time 10 minutes per site.103 The same group reported on a cohort of eleven subjects with persistent cognitive dysfunction and treated with a similar NILT protocol for chronic mTBI.132 The eleven subjects received NILT with a device with three LED cluster heads (Model 1100; MedX Health, Toronto, ON, Canada). The parameters used for the treatment were the following: NIR wavelength 870 nm and 633 nm (red light), irradiance 22.2 mW/cm2, fluence 13 J/cm2, and approximate time 10 minutes per site. The NIR light was applied three times per week for 6 weeks (18 sessions), on eleven sites for 10 minutes per site (the total duration of each session was 20 minutes).132 The sites on the skull were chosen on the midline, and bilaterally on frontal, parietal, and temporal areas. At the follow-up neuropsychological testing, NILT had a powerful effect on attention, inhibition, and inhibition switching in the Stroop task, and similarly improved verbal learning and memory, as well as enhanced long-delay free recall on the California Verbal Learning Test. Eight subjects, from the same cohort, were identified as having mild, moderate, or severe depression based on the BDI-II total score (range: 15-34).132 The three cases, who entered the study with only mild depression, remained the same after NILT treatment. Results for the five cases with moderate-severe depression were as follows: two moderate cases improved to mild/minimal depression 8 weeks after the end of NILT series, and one severe case improved to moderate depression. Two moderate or severe depression cases remained the same after 8 weeks of follow-up from the last NILT session.132 Dose response and photonic penetration A prevailing theory in photobiomodulation postulates that a bimodal response curve exists for the biological effects of NIR light.95 The so-called Arndt-Schulz curve (a fundamental principle in homeopathic medicine) is frequently used to describe this biphasic dose response. Some data indicate that low levels of light have a much better effect on stimulating and repairing tissues than higher levels of light. Laboratory studies of cells in culture have demonstrated a bimodal dose response to light exposure in lymphocytes133 and fibroblasts.134,135 For example, Chen et al135 found that a range of 0.03-0.3 J/cm2 was beneficial in activating transcription factors in culture, while 3-30 J/cm2 inhibited the activation of these factors. In contrast, an order-of-magnitude greater dose (2 J/cm2) was best at activating fibroblasts in a superficial wound model.136 Furthermore, an order-ofmagnitude greater dose (30 J/cm2) proved to be best in a rodent joint inflammation model.137 Thus, a dosedependent effect for many biological responses to NIR light has been demonstrated,95,137-139 but the critical parameter is dose at the level of the target tissue, rather than at the surface.137,140 The amount of energy that reaches a volume of tissue at depth is determined by the attenuation of the photonic energy as it passes through the overlying tissue. For example, only 2.45% of the energy from a 980 nm laser emitter penetrates to the level of the peroneal nerve.140 Nevertheless, the biphasic dose response does not appear to be universally true. In primary microglial cell culture, a dose-dependent response to NIR was demonstrated with no detrimental effects at doses as high as 30 J/cm2.141 So a critical question in the use of NILT is that of radiant energy penetration. In particular, some authors have challenged the efficacy of low-power LEDs used in LLLT.142-144 In laboratory studies, LLLT radiant energy is almost entirely absorbed in the first 1 mm of skin.145,146 In two unrelated studies, LLLT diode devices proved to be ineffective in the treatment of diabetic neuropathy,142,144 in contrast with prior reports.147 Similarly, laboratory studies of NILT using LLLT transcranially have not consistently yielded positive results. For example, in a rat model of TBI, Giacci et al148 found no benefit from daily 30-minute irradiation with either 670 nm or 830 nm 0.5 W LED emitters for a period of 7 days. Doses at the skin surface were 28.4 J/cm2 and 22.6 J/cm2, respectively.148 Similarly, treatment of a rat model of contusive spinal cord injury with LLLT (830 nm at 22.6 J/cm2 or 670 nm at 28.4 J/cm2) for 30 minutes per day for 5 days resulted in no significant functional improvement and no reduction in lesion size, despite delivering 2.6 J/cm2 to the spinal cord.148 Lapchak102 reported that the physical parameters of NILT in the clinical trials for the treatment of stroke utilized in the NEST-1 and NEST-2 trials116-120 may have delivered insufficient energy to cortical tissues to be effective. Therein, NIR light of 808 nm wavelength with infrared energy densities of 0.9 J/cm2 was applied to the human scalp for a total of 40 minutes with applications at multiple sites during that time.116,118 Recall that animal models of both stroke and TBI suggest that NIR energy densities in the range of 0.9-36 J/cm2 resulted in significant biochemical and behavioral changes.96,106-115,125-127 The concern raised from the NEST studies102 is that current clinical trials testing the effectiveness of lowenergy NIR diodes to treat TBI may yield negative or inaccurate efficacy data, not because of a failure of infrared light to invoke a change but due to a dose error. Doses that are effective when directly applied to cells in a Petri dish149,150 or to 3-5 mm thick rodent brains96,109-111,125,126,128 may be insufficient to penetrate 2-4 cm into the human brain. In a companion paper, our own studies of photonic energy penetration are detailed.105 To summarize, the laboratory tissue studies showed that 0.5 W LED emitters did not penetrate the 2 mm thickness of human skin. No detectable energy from 0.5 W LED NIR light emitters could be detected penetrating a similar thickness (1-2 mm) of sheep skin or 3 cm thick section containing sheep skin, skull, and brain. In contrast, 11% of the photonic energy from a 10 W 810/980 nm coherent NIR laser penetrated 2 mm of human skin. Similarly, 17% of the photonic energy from a 15 W 810 nm coherent NIR laser penetrated the same distance.105 Energy from these more powerful NIR emitters could be detected penetrating 3 cm of sheep skin, skull, and brain with 0.4% of the 10 W 810/980 nm NIR laser’s energy reaching the depth of 3 cm and 2.9% of the 15 W 810 nm NIR laser’s energy traversing the same distance.105 Anders also has demonstrated penetration of 808 nm light to 40 mm in the brain using a 5 W laser emitter (JJ Anders, personal communication, January 2015). Prompted by the mixed results in the literature and the observations by Lapchak,102 Franzen-Korzendorfer et al,144 Wan et al151 and Lavery et al142 we have been utilizing relatively high-power (10- 5 W) lasers at the wavelengths of 810 nm and 980 nm in the clinic to treat patients with TBI. Clinically, the patients have shown excellent responses with resolution of many of their long-standing symptoms of TBI or post-concussive syndrome. Below is a retrospective series of such patients to illustrate the extent and character of response to this modality. Methods Patients in the case series were sequentially treated patients at a clinic which is engaged in ongoing NILT for a number of clinical conditions. The risks, benefits, and current state of research on the use of NILT were explained to each patient. Each patient consented to treatment. Institutional Review Board approval was obtained in a post hoc review, noting that the risk-benefit ratio was acceptable. Between March 16, 2011 and February 20, 2013, sequential new referrals for chronic mild-to-moderate TBI were evaluated for treatment and selected for NILT using Class IV lasers, either the LT1000 (LiteCure, Newark, DE, USA), a 10 W adjustable NIR laser emitter with wavelengths of 810/980 nm capable of delivering continuous or pulsed NIR light, or the Diowave 810 (Diowave, Riviera Beach, FL, USA), an adjustable NIR emitter up to 15 W with a wavelength of 810 nm capable of delivering continuous or pulsed NIR energy. Demographics and laser treatment settings are detailed in Table 1. The fluence delivered to the skin of patients ranged from 55 J/cm2 to 81 J/cm2. No other treatment modalities (medications, exercise regimen, supplements) were added, discontinued, or changed while receiving NILT. Symptoms were monitored clinically. A baseline Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR)152 was completed for all patients, and the BDI153 was administered to seven of the ten patients before and after the course of treatment. In addition, each patient was instructed on how to create and maintain a patient and spousal diary of symptoms and subjective progress. Each of six patients received a single series of ten treatments with the LT1000 Class IV laser. Three additional patients each received a single series of 20 treatments with the LT1000 Class IV laser. One patient was treated with the Diowave 810 nm Class IV laser device in a series of 20 treatments. The patients and treating clinician wore protective eyewear. There were no incidents of burns or thermal discomfort (Figure 2). The impact of high-watt NILT While the patient group represented a diverse mix (Table 1 presents demographics), some notable commonalities of symptoms emerged. Over 90% of the patients had complaints of anxiety, depression, irritability, and insomnia. Other symptoms included headache (60%), suicidal ideation (50%), cognitive difficulties (50%), attention problems (50%), short-term memory problems (40%), loss of libido (30%), substance abuse (20%), fatigue (20%), and panic attacks (20%). Six of the patients were unemployed prior to treatment. Three of the patients were experiencing severe marital difficulties. All carried or had a confirmed diagnosis of TBI, but other comorbid diagnoses included PTSD, major depressive disorder, generalized anxiety disorder, bipolar disorder, and attention deficit/hyperactivity disorder. The patients’ baseline scores on the BDI were 25.3±12.1 (moderate depression range), and baseline scores on the QIDS-SR were 12.9±4.6 (moderate depression range). During NILT treatments, skin temperature increased no more than 3°C with rapid cooling after removal of the NIR light. A continuous sweeping motion was utilized to minimize skin heating and cover a larger area. After a course of ten treatments of NILT (20 treatments in four patients), each patient experienced significant clinical improvement with resolution of many of their symptoms (Table 2). In addition, the BDI scores dropped to 12±6.5 (nondepressed range). This represented a significant decrease (P,0.01, Student’s t-test, one-tailed, Microsoft Excel). The QIDS-SR scores after treatment were 2.2±2.3 (nondepressed range), and the difference from baseline was highly significant (P,0.00001, Student’s t-test, one-tailed). Patients noted improvement in cognitive function, mood, anxiety, and sleep. None of the patients continued to have suicidal thoughts (50% at baseline). Other symptoms, such as anxiety and irritability, were markedly improved. Most notable were the nonquantifiable changes in patients’ lives. Patients reported improved cognitive ability and a desire to return to meaningful work. Five of the six unemployed patients have returned to work. The two patients who were Iraq/ Afghanistan veterans have found new careers in highly skilled trades. The patients with marital difficulties have reconciled and were purchasing homes or otherwise solidifying their marriages. The clinical change can be attributed to NILT because no changes in medications, supplements, or exercise regimen were permitted during the course of NILT treatment. All patients in the case series experienced significant clinical improvement which supports the conjecture that high-power NIR laser delivers sufficient energy to the human brain for photobiomodulation to occur. Insomnia and suicidal ideation, common symptoms in those with TBI or post-concussive syndromes,3,17-20,24,25 resolved in 100% of cases. Headache, another common symptom for patients following a TBI,6,14,15,23 was reduced or resolved in the six patients so afflicted. Symptoms such as anxiety,14,15,21,24 depression,21,24,25,27-29 and irritability resolved or were dramatically reduced in all patients. Cognitive function appeared to improve based on return to work or improved work performance, although cognitive tests were not performed. The quality of life dramatically improved in all cases, based on the observations of the patients, their family members, and the treating clinician. At follow-up intervals of 6-7 months post-treatment, patients have reported continued improvements in symptoms. The precise areas of brain injury were not elucidated in Figure 2 Treatment parameters per individual, based on area of the skull treated. Notes: Dimensions varied per head/skull size and hair line. Treatment was warm and comfortable for each patient. There were no incidences of discomfort. Areas treated were (A) temporal- ilateral, (B) frontal, and in patients 1-3, 5, and 6 (B) frontal only. Table 1: Infrared light treatment parameters for each of the ten patients in the case series Patient Area treated Sex Mechanism of TBI Interval since TBI Wavelength of Dosage per area Duration before treatment NIR-PT dual wave Scanning technique per area pulsed 10 Hz 1 B, bilateral frontal Male Concussive blast 2 years 810 and 980 nm 2,700 J 10 minutes Fluence – 20.45 J/cm2 2 areas Area – 132 cm2 10 visits 2 B, bilateral frontal Female MVA 18 years 810 and 980 nm 2,400 J 9 minutes Fluence – 18 J/cm2 2 areas Area – 133 cm2 10 visits 3 B, bilateral frontal Female MVA 5 years 810 and 980 nm 2,400 J 8 minutes Abuse Fluence – 18.3 J/ cm2 2 areas Area – 131 cm2 10 visits 4 A–B, bilateral frontal, left temporal Female MVA x2 8 years and 13 years 810 and 980 nm 2,400 J 8 minutes Fluence – 18.3 J/cm2 3 areas Area – 131 cm2 10 visits 5 B, bilateral frontal Male Vietnam Veteran 20+ years 810 and 980 nm 3,000 J 10 minutes Concussion Fluence – 28.3 J/cm2 2 areas Child abuse Area – 106 cm2 10 visits 6 B, bilateral frontal Male Concussion 5+ years 810 and 980 nm 2,400 J 12 minutes Fluence – 14.8 J/cm2 2 areas Area – 162 cm2 10 visits 7 B–A, bilateral frontal, left temporal Male Afghanistan, Iraqi Disability 810 and 980 nm 3,000 J 10 minutes Disability due to TBI 2 years Fluence – 22.7 J/cm2 3 areas Area – 132 cm2 20 visits  B–A, bilateral frontal, bilateral temporal Female Hypoxic encephalopathy Childbirth-related 810 and 980 nm 2,700 J 9 minutes injury, 8 years Fluence – 27.8 J/cm2 3 areas Area – 97 cm2 20 visits 9 B–A, bilateral frontal, bilateral temporal Male MVA-TBI Numerous episodes 810 and 980 nm 3,000 J 10 minutes Concussions Fluence – 22.72 J/cm2 3 areas Area – 132 cm2 20 visits 10 B–A, bilateral frontal, left temporal Female Bicycle vs car >30 days 810 nm single 2,700 J 9 minutes Concussion, amnesia, LOC wavelength – Fluence – 17.1 J/cm2 3 areas different device Area – 158 cm2 20 visits Note: All safety precautions were followed, including metal protective eyewear (laser eye protection). Abbreviation: LOC, loss of consciousness; MvA, motor vehicle accident; TBi, traumatic brain injury. the majority of these cases, so a correlation of symptoms changes and cortical function changes cannot be made; however, perfusion SPECT imaging in other patients has shown significant increases in perfusion in injured areas of the brain and overall improved cortical function following similar courses of high-watt NILT.154 One concern that has been expressed about high-watt NIR lasers is the risk of tissue heating.155 We explored this issue in our companion paper on NIR penetration.105 Temperature change was 1°C-3°C at the skin surface using continuous-wave NIR lasers in the range of 10-15 W. Using pulsed settings, the high-powered lasers showed no significant temperature change in tissue samples. The temperature change on human skin was 1°C or less in the in vivo penetration studies while maintaining continuous movement of the laser probe head.105 Clinically, patients in this case series reported only slight warming of the skin, but no discomfort, using the continuous motion technique. Laboratory studies have largely focused on treatment of acute brain injury. The processes involved in the benefits of NIR light in chronic TBI as seen in this clinical case series may be quite distinct. Nevertheless, Schiffer et al156 found that a single application of LLLT at 810 nm and 250 mW to the forehead over 8 minutes reduced depression and anxiety symptoms in ten patients for approximately 2 weeks. Similarly, the small case series by Naeser et al103 demonstrated some benefit using NIR light, albeit at very low power levels over a prolonged course of several months with only transient benefit. Together with our clinical data, these findings suggest that at least some of the photobiomodulatory effects of NIR energy likely do occur in chronic neurological conditions. Prior presentations on NILT for the treatment of TBI or stroke in humans have focused on getting photonic energy through the skull to the cortex surface which traverses a distance of about 6-10 mm; however, this model is flawed in that the distance to the areas of damage may be far greater. In other words, the cortex immediately subjacent to a portion of the skull may be 10 mm from the surface, but the NIR light energy may need to penetrate 3-7 cm to reach areas of damage. Much of the cortical surface is actually lining the walls and floors of sulci, rather than immediately subjacent to the skull. Analysis of NIR spectroscopy reveals that light propagation through varying media with irregular boundaries is subject to high levels of scatter.157 In addition, review of the neuroimaging literature on TBI has revealed that the most common areas injured in TBI are the orbitofrontal cortex (at the ventral surface of the frontal lobe) and the anterior and medial temporal lobes.158 It is not anatomically possible to position an NIR light emitter immediately exterior to the skull overlying these areas. Indeed, the orbitofrontal cortex positioned immediately above the eyes can only be reached from the forehead by angling the light emitter. Similarly, the temporal lobes are separated from the surface by epidermis, dermis, subcutaneous fat, subcutaneous blood vessels, accessory head of the temporalis muscle, connective tissue, temporalis muscle, skull, and dura mater.159 Each of these structures has different absorption and refraction properties, and each interface between different materials also creates a barrier to transmission of photonic energy.157 Blood flowing in the subcutaneous vessels is believed to create a unique barrier to transmission.160 In summary, effectively targeting the areas most commonly injured in TBI with sufficient photonic energy to initiate reparative processes represents a significant challenge in NILT. This appears to have been overcome with the high-power laser protocol presented here and in a related paper.154 As yet, the mechanism of action of NILT in treating TBI is not entirely clear. Moreover, the neurological benefits are not immediately apparent. Rather, a delay of 1-4 weeks was noted, consistent with a progressive regeneration cascade set in motion by the NILT.96,103,105 ,107,109,121,122,124,127,135 Similarly, most of the patients in the present case series did not notice benefits immediately or within the first few treatments. Instead, they reported benefits emerging over an interval of weeks, and in some cases, continuing after completion of the course of NILT. In addition, the clinical improvement reported by the patients in the above case series is more profound than that reported by patients treated with LLLT or low-powered lasers.103 In fact, we observed that among seven subjects with documented moderate depression, per BDI scores, four had an antidepressant response (≥50% decrease of depression severity). In contrast, Naeser et al132 reported that out of eight subjects with TBI and comorbid depression, only three had a significant improvement in their depressive symptoms (37.5%). Our results may be due to the greater penetration of more powerful, coherent, and pulsed NIR light from a laser source. A unique outcome measure was developed for this protocol (Morries and Henderson, unpublished data, 2015). A patient diary and separate spousal diary provided a weekly update of patient’s response in his or her home environment. This novel approach to capturing the patient treatment experience provided the patient and family with tangible and pertinent documentation of the clinical response. While time consuming, the experiences recorded in these diaries proved to be valuable clinical tools to the treating clinicians.

CONCLUSION

To date, there has been little progress in developing effective treatments for chronic mild-to-moderate TBI or repetitive concussions. This area of need has become even more pressing with the return of veterans from military conflicts in Iraq and Afghanistan4,6,7,16,17,19,161 and the recognition of the magnitude of sport-related TBI.5,8-10 In addition, the dramatic growth in the geriatric population with attendant proprioceptive dysfunction has resulted in a rising incidence of fall-related TBI.162 NILT has shown promise as a tool for the treatment of TBI. A critical issue is to assure that adequate photonic energy reaches the injured areas of the brain. The use of high-wattage lasers, as we have demonstrated, results in marked clinical improvement in patients with chronic TBI. Moreover, symptoms consistent with PTSD, anxiety, and/or depression also improved considerably or resolved in this group of patients. Further work in the use of highwattage NILT in the treatment of TBI, depression, and other neurological disorders is encouraged.

ACKNOWLEDGMENTS

The authors would like to acknowledge the technical assistance of Mr Charles Vorwaller (Aspen Lasers) and Lite Cure Corporation. The authors also acknowledge the contribution of Ms. Taylor Tuteur in the artistic creation of Figure 1.

DISCLOSURE

Dr. Larry D Morries is the CEO of Neuro-Laser Foundation, a nonprofit foundation. He has a private practice in Lakewood, CO. Theodore A Henderson is the president of The Synaptic Space, a medical consulting firm. He is Table 2 NiLT case series with demographics, symptoms, and treatment response

PRETREATMENT POSTTREATMENT

Patient # Sex Occupation Mechanism of TBI Diagnoses Sleep Symptoms Suicidal BDI Sleep Symptoms Suicidal BDI 1 M Veteran, Blast – 5 years; TBI, PTSD, MDD Primary and H, S, I, D, X, L, A, M, + – Resolved None, back No – unemployed Iraqi middle C, SL with spouse, insomnia working 2 F Nurse, MVA – 8 years TBI, PTSD Middle and H, F, I, X, C, A, STM, L, + 18 Resolved A and HA – No 15 unemployed terminal HA, SL but mild, insomnia return to work 3 F Unemployed Assault and TBI, PTSD, MDD, Primary and D, X, P, M, L, HA, S, + 23 Resolved HA – mild, No – MVA, 5 years GAD, ADHD middle insomnia, SA, C, N, STM back with Prior nightmares spouse, no SA, working 4 F Unemployed MVA – 3 years, TBI, PTSD, MDD Primary and D, X, HA, I, M, SA, S, N + 23 Resolved None, marriage No 17 assault middle insomnia, improved, numerous violent nightmares no SA, working 5 M Veteran, Blast – 20+ years TBI, MDD, GAD Primary and D, X, I, S, SL + 18 Resolved None No 1 unemployed 1960s; Vietnam middle insomnia 6 M executive Trauma – TBI, GAD, MDD Primary D, X, I, P, HA, A, S – – Resolved HA, X, and P – No – chronic insomnia but improved 7 M Veteran, Multiple blasts TBI, MDD, GAD Primary and S, D, I, X, C, A, S, STM, – 22 Resolved HA and C – No 16 disability (>12); Afghan middle HA mild, new and Iraqi wars insomnia career 8 F Student Childbirth TBI, learning Primary D, I, X, C, A, SL, F, STM – 16 Resolved, STM improved, No 7 disorder insomnia no bads reading .20% dream more animated 9 F Sales MVA and TBI, LOC Primary and HA, SL, N, D, I, X, H, A – 29 Resolved Mild HA, No 9 sports TBI middle insomnia, job nightmares promotion 10 F Physicist Recent car– TBI, LOC, amnesia Primary and D, I, X, neck, knee pain – 51 Resolved No loss No 19 bicycle middle of skills, accident insomnia maintain intellectual job Notes: Demographics for each of the ten patients in this case study is presented. Also presented is their history of mechanism of injury, diagnosis, and related symptoms. Changes in anxiety levels, sleep patterns, depression, and suicidal ideation were important symptoms and outcomes to track. Patients were instructed for no medication changes, with their primary treatment provider’s approval. Cognitive difficulties, attention problems, and short-term memory difficulties were by patient interpretation of their symptomatic improvement and patient diary changes. Symptom occurrence % was as follows: Anxiety – 100%, Depression – 90%, Irritability – 90%, Primary And Middle Insomnia – 90%, Headache – 60%, Sadness – 60%, Suicidal Ideation – 50%, Cognitive Difficulties – 50%, Attention Problems – 50%, Short-Term Memory Problems – 40%, Marital Difficulties – 30%, Loss Of Libido – 30%, Substance Abuse – 20%, Fatigue – 20%, Panic Attacks – 20%. Abbreviations: NILT: Near-Infrared Light Therapy, TBI: Traumatic Brain Injury, PTSD: Post-traumatic Stress Disorder, MDD: Major Depressive Disorder, GAD: General Anxiety Disorder, ADHD: Attention Deficit/Hyperactivity Disorder, H: Hyperarousal, S: Sadness, I: Irritability, D: Depression, X: Anxiety, L: Loss Of Libido, A: Attention Problems, M: Marital Difficulties, C: Cognitive Problems, SL: Sleep Issues, F: Fatigue, STM: Short- erm Memory Problems, HA: Headache, P: Panic Attacks, SA: Substance Abuse, N: Nightmares, BDI: Beck Depression Inventory, LOC: Loss of Consciousness, MVA: Motor Vehicle Accident. the president of Dr. Theodore Henderson, Inc., a clinical service firm. He is the co-owner of Neuro-Luminance, a clinical service organization. He is the president of the International Society of Applied Neuroimaging. He is the CFO of the Neuro-Laser Foundation, a nonprofit foundation. Dr. Paolo Cassano received funding from the Brain and Behavior Research Foundation; Photothera Inc and from the Dupont Warren Fellowship (Harvard Medical School) to conduct research on NIR light for the treatment of major depressive disorder.

ABOUT THE AUTHORS:

Larry D. Morries, DC brings a distinguished 30-year career studying and treating the brain and body through his private practice based in Lakewood, Colorado. As Neuro-Laser Foundation’s co-founder, his chiropractic expertise is complemented with extensive study of near infrared-light therapy applications, clinical radiology, clinical neurology and sports injury and rehabilitation. In practice since 1973, Dr. Morries has contributed extensively to both chiropractic and medical professions throughout his career. He is a recognized expert often called upon for review services, treatment utilizations, and documentation presentations. In recent years, he has guided the Colorado State of Colorado Workers Compensation Board with a review of treatment guidelines for Chronic Pain, and Complex Regional Pain Syndrome, Shoulder Pain, Low Back Pain, Traumatic Brain Injury, and was asked to present in 2016 on Thoracic Outlet Syndrome.

Other professional involvement include:

• Colorado Chiropractic Association, Board member, President in 1982, Chairman in 1984

• Colorado Chiropractic Society, Vice President and Secretary in 1995-2004

• Colorado Chiropractic Journal Club, Chairman,since 2008

Dr. Morries has continued his study of the human body and brain with postgraduate work in Neurodiagnostic testing at the American Academy of Neurology, and Harvard Medical School-Massachusetts General Hospital. He is also educated on Spinal Mechanics at Chicago Rehabilitation Institute. He earned his Doctorate in Chiropractic from Logan Chiropractic College, with recognition as Student Clinical Director, Teaching Assistant in Radiology. Dr. Morries is most proud of his research papers and awards, in America Academy of Pain Medicine, Sciatic and Suprascapular Nerve Blocks with Dr. Steve Gulevich, MD. He was asked to share two Poster presentations at the North American Laser Foundation in 2011on Low Back Pain, plus Polyneuropathy treatment with Laser (NIR) therapy. His Podium Presentation and publication on Hip dysplasia, in American Board of Chiropractic Sports Physicians®. Additionally, he has given presentations abroad at State of Chiropractic Research, Foundation of Chiropractic Education and Research, in Bournemouth England and Vancouver, BC, Canada. Dr. Theodore Henderson has extensive training and experience to the practice of Psychiatry. He trained in Psychiatry at the prestigious Barnes/Jewish Hospitals at Washington University in St. Louis. Dr. Henderson completed a fellowship in Child & Adolescent Psychiatry at the University of Colorado. He also has training in Radiology, Nuclear Medicine, and the genetics of psychiatry. He established his private practice in Centennial Colorado in July of 2000. Dr. Henderson brings a unique blend of expertise in psychopharmacology, neurobiology, and an understanding of human nature to the practice of psychiatry. Dr. Henderson attended medical school at Saint Louis University School of Medicine. While in medical school, he began studying heart pathology under Dr. Vernon Fischer. He earned an American Heart Association Medical Student Research Fellowship. With this fellowship, he spent one year at the University of Washington studying the pathology of atherosclerosis. In 1991, Dr. Henderson founded the Child Abuse Prevention Task Force at Saint Louis University. This program taught children, parents, and teachers about child sexual abuse and how to prevent it. Each year, this program reached over 8,000 children throughout the metro St. Louis area, primarily in the poor inner-city schools. The program was awarded numerous awards, including a Saint Louis University Community Service Award, Commendations from the school districts, and an award from the American Medical Student Association. Dr. Henderson was nominated for a Student Life Leadership Award and earned a Departmental Award from the Department of Community and Family Medicine. He also received a Weis Humanitarian Award recognizing outstanding humanitarian care as a medical student. Dr. Henderson wrote a training manual on this program that was implemented at other medical schools and he cowrote a book chapter in the book, A Parent’s & Teacher’s Handbook on Identifying and Preventing Child Abuse (1998). During graduate school and medical school, Dr. Henderson published numerous research studies. He published 9 articles and 27 abstracts about his research in brain development. He also published a book chapter on brain development in collaboration with his research professor, Dr. Mark Jacquin. His research focused on the role of neural growth factors and impulse activity on the development of brain organization. He collaborated with leading researchers, including Drs. Thomas Woolsey, Eugene Johnson, and Thomas Rhoades. While a medical student, Dr. Henderson wrote two research grants (as part of program project grants). Both were funded. He continued conducting research at Saint Louis University and Washington University throughout his residencies. Dr. Henderson trained for one year in Radiology, focusing on neuroimaging and pediatrics. With this strong base, he then undertook a residency in Psychiatry at Washington University’s program at Barnes/Jewish Hospitals in St. Louis. His residency included extended training in general pediatrics at St. Louis Children’s Hospital. In 1997, He was awarded the National Institute of Mental Health Outstanding Resident Award for his ongoing work in child abuse prevention and his neurobiological research while a resident. Dr. Henderson completed a residency in Adult (or General) Psychiatry and then undertook a fellowship in Child Psychiatry at the University of Colorado. This included additional specialization in Autism and Autism Spectrum Disorders. He compl



Influence of Low Level Laser Radiation on Migration of Stem Cells

Levon Gasparyan, Grigory Brill, Anu Makela - (Publication)
This study showed a 26% increase in stem cell when they uses red and IR lasers continuous wave.
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 Abstract: The long term effects of low level laser therapy can involve treatment mechanisms connected with activation of stem cells.

In the current study migration of stem cells was tested under the influence of laser light alone as well as in case of combined influence of light and stromal cell-derived factor-1α (SDF-1α). This cytokine plays a role in lymphocyte trafficking, hematopoietic progenitor cell and stem cell homing.

To investigate the light influence on stem cells, we analyzed factor-dependent cell-Patersen (FDCP)-mix multipotent progenitor cells.

Migration of the stem cell line was tested using Transwell system (Corning, NY) under influence of red diode laser (λ=659.6 nm, 19.5 mW) or infrared diode laser (λ=958 nm, 36 mW) during 15 min at continuous wave, as well as in case of applying 150 ng/ml SDF-1α.

Group 1 cells were a group of control, group 2 cells received only red light irradiation, while group 3 cells had IR light irradiation. Group 4 cells were treated with 150 ng/ml SDF-1α. Group 5 cells were irradiated with red laser light in addition to 150 ng/ml SDF-1α, and group 6 cells by IR light and 150 ng/ml SDF-1α.

The count of migrated cells was 1496,5±409 (100%) in case of control. Red and IR laser light increased migration activity of stem cells up to 1892±283 (126%) and 2255,5±510 (151%) accordingly. Influence of SDF-1α was more significant, than effects of light irradiation alone 3365,5±489 (225%). Combined effects of light irradiation and SDF-1α were significantly stronger 5813±1199 (388%) for SDF-1α and red laser light, and 6391,5±540 (427%) for SDF-1α and IR laser light irradiation.

Preliminary study results showed that laser light irradiation can activate stem cell migration in vitro. The results are more reliable in the case of combined application of light and SDF-1α. These results are giving ground to consider that stem cell reactions to light irradiation can be one of the factors of light therapy.

Key words: low level laser irradiation, low level laser therapy, stem cells, SDF-1, stromal cell-derived factor-1

INTRODUCTION

More than 30 years ago first reports about biological effects of low doses of laser light were presented. Currently low level laser therapy (LLLT) is successfully applied in the treatment of numerous diseases and pathological conditions. LLLT exhibits positive effects for the treatment of disorders, having in common failure of blood supply with development of acute or chronic tissue hypoxia, different level of destruction of tissues, following decreased regenerative abilities of tissues and organs, defects in immune system, and altered cell metabolism. At the same time some important mechanisms of influence of laser light on the body are still far to be fully understood [1 - 8].

Recent studies discovered important role of bone marrow hematopoetic stem cell (HSCs) for naturally occurred recovery and regeneration processes, following tissue hypoxia and injury. The three clinically important steps in this natural process are mobilization of stem cells from the bone marrow, homing of these cells to the site of injury, and differentiation of the stem cell into a functional cell of the injured tissue [9]. Different methods of stem cell therapy, the treatment method, based on mobilization and transplantation of stem cells, proves to be effective method of therapy for different disorders.

We proposed a hypothesis that wide range of positive effects following laser therapy can be connected to increased activity of stem cells in damaged tissues. To test that, we examined in vitro the influence of laser light on migration of stem cells in absence and in presence of stromal cell-derived factor-1 (SDF-1), a potent chemoattractor for lymphocytes, monocytes, HSCs, which plays a critical role in the stem cell migration towards areas of tissue injury and hypoxia.

MATERIALS AND METHODS

To investigate the light influence on stem cells, we analyzed factor-dependent cell-Patersen (FDCP)-mix multipotent progenitor cells. The FDCP-mix stem cell line was maintained in ISCOVE’S medium supplemented with 20% horse serum and penicillin/streptomycin in the presence of 20 ng/ml IL-3. The cells were supplied with fresh medium each 5 days. Migration of the stem cell line was tested using Transwell system (Corning, NY). The cells were washed with PBS once and re-suspended in the medium containing 0.1% BSA (2x106/ml). Then, 600 μl of the mixture was irradiated by red diode laser (λ=659.6 nm, 19.5 mW) or infrared diode laser (λ=958 nm, 36 mW) during 15 min at continuous wave. Next, 100 μl of the mixture (2x105 cells) was seeded into upper chambers of the Transwell system, and the filters were placed into the wells containing 600? μl of the medium with or without 150 ng/ml SDF-1α. The plate was incubated for 4 h (37°C, 5% CO2, humidified atmosphere), after which the cells were collected and counted by a FACS sorter (Beckton Dickinson) during 1 min. All samples were performed in duplicate.

Group 1 cells are control group, group 2 cells received only red light irradiation, while group 3 cells – only IR light irradiation. Group 4 cells were treated with 150 ng/ml SDF-1α. Group 5 cells were irradiated with red laser light in addition to 150 ng/ml SDF-1α, and group 6 cells – IR light and 150 ng/ml SDF-1α.

RESULTS

Small amount of stem cells can migrate without SDF-1α or laser light influence. The count of migrated cells in control group was 1496,5±409 (Fig). This amount was considered as 100%. Red and IR laser light at the above mentioned dosage and methods of irradiation increased migration activity of stem cells up to 1892±283 (126%) and 2255,5±510 (151%) accordingly. Influence of SDF-1α was more noticeable, than effects of red or IR laser light irradiation alone - 3365,5±489 (225%). It is important to stress attention on the finding, that rate of stem cell migration towards the filter and SDF-1α containing medium was much higher after laser irradiation of cells - 5813±1199 (388%) for red laser light, and 6391,5±540 (427%) for IR laser light irradiation.

DISCUSSION

The main scientific result of this study is the fact, that red and infrared laser light irradiation can activate migration of stem cells in vitro. Moreover, red and IR laser radiation can up-regulate the rate of stem cell migration towards higher SDF-1α gradient.

How to explain the direct effects of mobility of stem cells in vitro under red and IR laser light irradiation, and use this fact for better understanding the wide range of therapeutic effects of laser therapy?

Modern medical science has accepted that every pathologic condition or disease should be treated according to its clinical stage and symptoms, considering its pathogenesis and etiology. Similar treatment methods can be applied only for the treatment of different diseases, having common pathogenesis.

Not very many examples of successful application of the similar or close therapy method for the treatment of different pathologies are known in modern medicine. Steroid hormone therapy is one of such cases.

Another illustration of successful application of the similar treatment techniques for treatment of different disorders is stem cell therapy, a novel treatment method, which is still under development. Growing data suggests, that transplanted stem cell can successfully and for long period of time improve heart myocardial contractility and other heart functions after myocardial infarction, can support neoangiogenesis in areas of tissue infarction and damage, can replace several cell types in tissues, including β-cells in diabetes models, neurons, cardiomyocytes, hematopoetic cells of different lineages and so on, as well as be useful in the treatment of atherosclerosis [9].

The main principle of stem cell therapy is the idea of replacement of damaged and dead cells in injured tissues and organs with new healthy ones. It is known, that severe stress, tissue hypoxia and damage mobilizes some hematopoetic stem cells (HSCs) from bone marrow to peripheral bloodstream. After that HSCs can migrate towards hypoxic tissues and reach them. Finally they can start to proliferate to the cells types, typical for that damaged tissues. HSCs in the tissues are also able to produce several cytokines, chemokines, growthfactors, improve survival of damaged cells and limit apoptosis. As a result of some tissue regeneration, improvement in the function of a damaged organ can be achieved. Similar and even stronger regeneration and treatment effects can be displayed after transplantation of fetal or adult HSCs to recipient [10-12].

Low laser light irradiation is one other example of application of the same factor for the treatment of number of disorders, which, at first glance, have nothing or very little in common in their pathogenesis. Laser light can accelerate wound and burn healing, improve condition of patients after myocardial infarction and stroke, can support hematopoiesis of bone marrow after X-ray radiation or during cancer chemotherapy, can help for the treatment of diabetic angiopathy and neuropathy, as well as reduce atherosclerotic plaque formation. In cellular and tissue level LLLT exhibits positive effects for the treatment of disorders, having in common failure of blood supply with development of acute or chronic tissue hypoxia, different level of destruction of tissues, following with decreased regenerative abilities of cells, as well as altered cell metabolism [6, 7, 13, 14].

One can see that the therapeutic applications of LLLT and stem cell therapy are very close. So, earlier we proposed the hypotheses that one of the mechanisms of light therapy includes acceleration of tissue repair due to better mobilization of stem cells to the spot of injury after laser light irradiation [15]. That process should include several phases, including activation of stem cell migration towards area of tissue damage and hypoxia.

Stem cells are being investigated for their potential use in regenerative medicine. Stem cells share the following two defining characteristics: the capacity to differentiate into a spectrum of different cell types and the capacity to renew themselves [16]. The biological principle that underlies stem cell therapy is tissue-directed differentiation. For example, adult stem cells isolated from liver tissue and re-injected into liver become hepatocytes, whereas the same cells injected into myocardium become myocytes. [17] Stem cells have been engrafted into a broad spectrum of tissues, including regenerating bone, neural tissue, dystrophic skeletal muscle, and injured skeletal muscle. [18]. Myocardial regeneration is perhaps the most widely studied and debated example of stem cell plasticity. The most promising results have been obtained after transplantation and mobilization of bone marrow cells to the area of infarction.

The three clinically important steps in this natural process are mobilization of stem cells from the bone marrow, homing of these cells to the site of injury, and differentiation of the stem cell into a functional cell of the injured tissue [19].

Stem cell repair of cardiac and vascular tissue is a naturally occurring process after injury [20, 21] Circulating CD34+ mononuclear cell counts and plasma levels of endothelial growth factor are significantly increased in patients with acute myocardial infarction, peaking on day 7 after onset [22]. Due to limitations of the naturally occurring repair process after myocardium infarction and other injuries or pathologies several stem cell transplantation strategies were proposed and tested.

At present, however, enthusiasm for the therapeutic potential of strategies of stem cell transplantation is limited by certain practical considerations. For example, the number of stem cells, required for injection for the treatment of myocardial infarction, can be harvested approximately from 6 l of donor blood [23].

Other important limitation for autologous bone marrow stem/progenitor cell mobilization is a recent finding, that circulating endothelial progenitor cells in patients with coronary heart disease are impaired with respect to number and functional activity. Moreover, Heeschen et al [24] reported that regeneration and functional ability of bone marrow-derived mononuclear cells (BM-MNCs) in patients with chronic ischemic cardiomyopathy (ICMP) are also limited. In spite of the fact that, the number of BM-MNCs isolated from bone marrow aspirates of 18 patients with ICMP and 8 healthy subjects s did not differ, the colony-forming capacity of BM-MNCs from patients with ICMP was significantly lower compared with BM-MNCs from healthy controls. Likewise, the migratory response to SDF-1 and vascular endothelial growth factor (VEGF) was significantly reduced in BM-MNCs derived from patients with ICMP compared with BM-MNCs from healthy controls. The reduced neovascularization capacity in vivo of BM-MNCs derived from patients with ICMP closely correlated with the in vitro assessment of SDF-1-induced migration and colony-forming capacity.

The need for development of new methods for mobilization, as well as for homing of stem cells to the site of injury is therefore evident.

Several growth factors, chemokines and cytokines are involved in the regulation of stem cell mobilization, homing and differentiation. Stromal cell-derived factor-1 (SDF-1) is one of them. SDF-1 is a chemokine playing an important role in the trafficking of hematopoietic stem cells. SDF-1 is expressed on stromal cells of various tissues. CXCR4 is the only known receptor for SDF-1 [25]. SDF-1/CXCR4 interaction is reported to play an important physiological role during embryogenesis in hematopoiesis, vascular development, cardiogenesis, and cerebellar development [26-28].

Recently, several investigators have reported that CD34+ cells, classically considered to be hematopoietic stem cells, expressed CXCR4, and that SDF-1 could induce CD34+ cell migration in vitro [29]. Accordingly, SDF-1 is considered as one of the key regulators of hematopoietic stem cell trafficking between the peripheral circulation and bone marrow. SDF-1 has also been shown to effect CD34+ cell proliferation and mobilization and to induce angiogenesis in vivo [30 -32].

Hattori et al [31] reported that plasma elevation of SDF-1 induced mobilization of mature and immature hematopoietic progenitors and stem cells, including endothelial progenitor cells (EPCs). However, application of granulocyte colony-stimulating factor (G-CSF) for stem cell mobilization is widely accepted nowadays.

Yamaguchi et al [23] studied the effects of SDF-1 on migration and accumulation of EPCs. SDF-1 induced EPCs migration in a dose dependent manner in vitro. The magnitude of migration was similar to that induced by VEGF. Authors also reported that locally (in hind-limb ischemic muscle of experimental animals) administered SDF-1 could augment the local accumulation of transplanted EPCs from peripheral blood, thereby resulting in enhanced neovascularization. As a result, cell transplantation not only improved neovascularization but also reduced adverse biological consequences such as limb necrosis and auto-amputation in the mouse ischemic hind-limb model. These studies also disclosed that systemic EPCs transplantation improved myocardial neovascularization and cardiac function corresponding to reduced left ventricular scarring. Authors concluded that, at least under the experimental conditions used in the study, the effect of SDF-1 on neovascularization appears to result primarily from its ability to enhance the recruitment and incorporation of transplanted EPCs.

Damas at al. [33] reported that SDF-1α, at least in high concentrations, may mediate anti-inflammatory and matrix-stabilizing effects in unstable angina. These effects may promote plaque stabilization, and therapeutic intervention that enhances SDF-1 α activity could potentially be beneficial in acute coronary syndromes. Authors demonstrated significantly altered SDF-1/CXCR4 expression in patients with angina, with particularly marked changes in those with unstable disease, with low SDF-1 levels in plasma and altered expression of its corresponding receptor on peripheral blood mononuclear cells (PBMC). In contrast to the raised plasma levels of inflammatory chemokines in patients with angina plasma levels of SDF-1 and the surface expression of its corresponding receptor (CXCR4) on PBMC appear to be down-regulated in these patients. Thus, although persistent inflammation may involve up-regulation of inflammatory chemokines, recent studies suggest that inflammatory cytokines (eg, TNF-α and IL-1) may decrease the expression of SDF-1 and CXCR4.

Future progress of stem therapy techniques probably will include development of incubation methods for enhancement stem cell mobility and homing ability, as well as for faster proliferation into desire tissue cells. Increasing migration abilities will help to achieve better and faster results.

The ability of laser light to activate migration and mobility of different cells is well known. It was noticed, that irradiation of sperm cells in vitro can increase their mobility and fertility [34]. Moreover, this effect is more pronounced in case of damaged cells with low mobility rate. This gives a ground to assume that laser light irradiation in certain dosage and condition can improve functional abilities of cells. Future experiments are required to ascertain if stem cells respond to the laser light the same way.

The main finding on this study is that red and IR laser light can stimulate stem cell migration in vitro, and especially increase migration towards SDF-1α gradient. Stem cell ability to migrate towards tissues with higher SDF-1 concentration is one of the key mechanisms of stem cell homing. These results are giving ground to speculate that activation of stem cell migration can be one of the mechanisms of low level laser therapy. Taking into consideration that the combined of SDF-1 and laser irradiation had the strongest effect on stem cell homing, it would be reasonable to assume that this combination could be used in not only increasing the activity of stem cells but also in determining the main area of stem cell mobilization and homing. The current study did not aim to study the mechanisms of increased migration ability, which will be study in the future. But it is possible to suggest following explanation: laser irradiation can change the metabolism of stem cells, increase ATP production and so increase the migration, as well as up-regulate CXCR4 receptor expression or syntheses de novo. More studies are required to test if the laser light irradiation in vivo is able to make homing of transplanted stem cells to the area of damage more efficient, to check the influence of laser light on the mobilization rate of stem cells from bone marrow, to investigate if laser light can enhance functional abilities of stem cells. These studies would be desirable for better understanding of the mechanisms of laser therapy and for development of more effective methods of stem cell therapy.

References

1. Tuner J. and Hode L. Low Level Laser Therapy: Clinical Practice and Scientific Background, Prima Books, Grängesberg, Sweden, 1999.

2. Karu T. The Science of Low Power Laser Therapy, Gordon & Breach, London, 1998.

3. Baxter G.D. Therapeutic Lasers: Theory and Practice, Churchill Livingstone, London, 1994.

4. Simunovic Z., Ed. Lasers in Medicine and Dentistry, Vitgraf, Rijeka (Croatia), 2000.

5. Zhukov B.N. and Lysov N.A. Laser irradiation in experimental and clinical angiology (in Russian), Samara (Russia), 1996.

6. Kozlov V.I., et al. Bases of laser physio- and reflexo-therapy (in Russian), Zdorovje, Samara (Russia), 1993.

7. Paleev N.R. Ed. Phototherapy (in Russian), Meditsina, Moscow (Russia), 2001.

8. Skobelkin O. K. Ed. Application of low-intensive lasers in clinical practice (in Russian). Moscow, 1997.

9. Forrester J, Price M, Makkar R. Stem Cell Repair of Infarcted Myocardium. An Overview for Clinicians. Circulation. 2003;108:1139–1145.

10. Orlic D., Hill J., Arai A. Stem Cells for Myocardial Regeneration Circulation Research. 2002;91:1092.

11. Hodgson D., Behfar A., Zingman L.V., Kane G.C., Perez-Terzic C., Alekseev A.E., Puceat M., and Terzic A. Stable benefit of embryonic stem cell therapy in myocardial infarction. Am J Physiol Heart Circ Physiol, August 1, 2004; 287(2): H471 - H479.

12. Ozbaran M., Omay S. B., Nalbantgil S., Kultursay H., Kumanlioglu K., Nart D., and Pektok E. Autologous peripheral stem cell transplantation in patients with congestive heart failure due to ischemic heart disease. Eur. J. Cardiothorac. Surg., March 1, 2004; 25(3): 342 - 350.

13. Brill A.G., Shenkman B., Brill G.E. et al. Blood irradiation by He-Ne laser induces a decrease in platelet responses to physiological agonists and an increase in platelet cyclic GMP. Platelets. 2000. Vol. 11. P. 87-93.

14. Mester A. Biostimulative effect in wound healing by continuous wave 820 nm laser diode. Lasers in Med Science, abstract issue July 1988, No. 289.

15. Gasparyan L.V. Stem cells and therapeutic effect of light irradiation (in Russian). Collection of abstracts of the 10th International Conference of Quantum Medicine, Moscow, 2003, pp. 43-44.

16. Graf T. Differentiation plasticity of hematopoietic cells. Blood. 2002;99:3089–3101.

17. Malouf NN, Coleman WB, Girsham JW, et al. Adult-derived stem cells from the liver become myocytes in the heart in vivo. Am J Pathol. 2001;158:1929–1935.

18. Donovan PJ, Gearhart J. The end of the beginning for pluripotent stem cells. Nature. 2001;414:92–97.

19. Forrester J, Price M, Makkar R. Stem Cell Repair of Infarcted Myocardium. An Overview for Clinicians. Circulation. 2003;108:1139–1145.

20. Beltrami AP, Urbanek K, Kajstura J, et al. Evidence that human cardiac myocytes divide after myocardial infarction. N Engl J Med. 2001;344:1750–1757.

21. Gill M, Dias S, Hattori K, et al. Vascular trauma induces rapid but transient mobilization of VEGFR2(+)AC133(+) endothelial precursor cells. Circ Res. 2001;88:167–174.

22. Shintani S, Murohara T, Ikeda H, et al. Mobilization of endothelial progenitor cells in patients with acute myocardial infarction. Circulation. 2001;103:2776–2779.

23. Yamaguchi J, Kusano K, Masuo O, at al. Stromal Cell–Derived Factor-1 Effects on Ex Vivo Expanded Endothelial Progenitor Cell Recruitment for Ischemic Neovascularization. Circulation. 2003;107: 1322–1328.

24. Heeschen C, Lehmann R, Honold J, Assmus B, Aicher A, Walter DH, Martin H, Zeiher AM, Dimmeler S. Profoundly reduced neovascularization capacity of bone marrow mononuclear cells derived from patients with chronic ischemic heart disease. Circulation. 2004;109(13):1615-22.

25. Bleul CC, Farzan M, Choe H, et al. The lymphocyte chemoattractant SDF-1 is a ligand for LESTR/fusin and blocks HIV-1 entry. Nature. 1996;382:829–833.

26. Nagasawa T, Hirota S, Tachibana K, et al. Defects of B-cell lymphopoiesis and bone-marrow myelopoiesis in mice lacking the CXC chemokine PBSF/SDF-1. Nature. 1996;382:635–638.

27. Tachibana K, Hirota S, Iizasa H, et al. The chemokine receptor CXCR4 is essential for vascularization of the gastrointestinal tract. Nature. 1998; 393:591–594.

28. Zou YR, Kottmann AH, Kuroda M, et al. Function of the chemokine receptor CXCR4 in haematopoiesis and in cerebellar development. Nature. 1998;393:595–599.

29. Mohle R, Bautz F, Rafii S, et al. The chemokine receptor CXCR-4 is expressed on CD34+ hematopoietic progenitors and leukemic cells and mediates transendothelial migration induced by stromal cell-derived factor-1. Blood. 1998;91:4523–4530.

30. Lataillade JJ, Clay D, Dupuy C, et al. Chemokine SDF-1 enhances circulating CD34+ cell proliferation in synergy with cytokines: possible role in progenitor survival. Blood. 2000;95:756–768.

31. Hattori K, Heissig B, Tashiro K, et al. Plasma elevation of stromal cell-derived factor-1 induces mobilization of mature and immature hematopoietic progenitor and stem cells. Blood. 2001;97:3354–3360.

32. Salcedo R, Wasserman K, Young HA, et al. Vascular endothelial growth factor and basic fibroblast growth factor induce expression of CXCR4 on human endothelial cells: in vivo neovascularization induced by stromal derived factor-1α. Am J Pathol. 1999;154:1125–1135.

33. Damas J, Wæhre T, Yndestad A, et al. Stromal Cell–Derived Factor-1a in Unstable Angina. Circulation. 2002;106:36-42.

34. Pyrikova S.I et al. Effect of laser exposure on human seminal fluid (in Russian). Clinical and laboratory diagnosis. 1998;5:15-16.



NASA Light Technology Successfully Reduces Cancer Patients Painful Side Effects from Radiation and Chemotherapy

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Glowing red light from High Emissivity Aluminiferous Luminescent Substrate, or HEALS technology, has been proven to aid in the healing of human wounds, burns, diabetic skin ulcers and oral mucositis.Glowing red light from High Emissivity Aluminiferous Luminescent Substrate, or HEALS technology has been proven to aid in the healing of human wounds, burns, diabetic skin ulcers and oral mucositis. (NASA/MSFC/Higginbotham) 

A nurse in the Bone Marrow Transplant and Cellular Therapy Unit at the University of Alabama at Birmingham Hospital demonstrates use of a WARP 75 device.A nurse in the Bone Marrow Transplant and Cellular Therapy Unit at the University of Alabama at Birmingham Hospital demonstrates use of a WARP 75 device. (NASA/MSFC/Higginbotham) 
View all imaA NASA technology originally developed for plant growth experiments on space shuttle missions has successfully reduced the painful side effects resulting from chemotherapy and radiation treatment in bone marrow and stem cell transplant patients.In a two-year clinical trial, cancer patients undergoing bone marrow or stem cell transplants were given a far red/near infrared Light Emitting Diode treatment called High Emissivity Aluminiferous Luminescent Substrate, or HEALS, to treat oral mucositis -- a common and extremely painful side effect of chemotherapy and radiation treatment. The trial concluded that there is a 96 percent chance that the improvement in pain of those in the high-risk patient group was the result of the HEALS treatment. "Using this technology as a healing agent was phenomenal," said Dr. Donna Salzman, clinical trial principal investigator and director of clinical services and education at the Bone Marrow Transplant and Cellular Therapy Unit at the University of Alabama at Birmingham Hospital. "The HEALS device was well tolerated with no adverse affects to our bone marrow and stem cell transplant patients." The HEALS device, known as the WARP 75 light delivery system, can provide a cost-effective therapy since the device itself is less expensive than a day at the hospital and a proactive therapy for symptoms of mucositis that are currently difficult to treat without additional, negative side effects. 
The device could offer patients several benefits: better nutrition since eating can be difficult with painful mouth and throat sores; less narcotic use to treat mouth and throat pain; and an increase in patient morale -- all of which can contribute to shorter hospital stays and less potential for infection, added Salzman. 

LEDs are light sources releasing energy in the form of photons. They release long wavelengths of light that stimulate cells to aid in healing. HEALS technology allows LED chips to function at their maximum irradiancy without emitting heat. NASA is interested in using HEALS technology for medical uses to improve healing in space and for long-term human spaceflight. 

Ron Ignatius, founder and chairman of Quantum Devices Inc., of Barneveld Wis., developed the WARP 75 light delivery system for use in the trial. The device uses the HEALS technology to provide intense light energy: the equivalent light energy of 12 suns from each of the 288 LED chips -- each the size of a grain of salt. It is one of many devices using HEALS technology, developed in collaboration with NASA. 

In the early 1990s, Quantum teamed with the Wisconsin Center for Space Automation and Robotics – a NASA-sponsored research center at the University of Wisconsin-Madison – to develop Astroculture 3, a plant growth chamber using near infrared HEALS technology for plant growth experiments on shuttle missions. Over the years, Quantum has worked to develop HEALS technology for use in medical fields, specifically with pediatric brain tumors and hard-to-heal wounds such as diabetic skin ulcers, serious burns and oral mucositis. 

"With the help of NASA's Innovative Partnerships Program, Quantum Devices and its medical partners have been able to take a space technology and adapt it for an entirely different application to significantly help people here on Earth," said Glenn Ignatius, president of Quantum Devices. "This collaboration between NASA and commercial companies has spurred innovation that is touching millions of lives on Earth -- for the better." 
The clinical trial was funded by NASA's Innovative Partnerships Program at the Marshall Space Flight Center in Huntsville, Ala. It included 20 cancer patients from Children's Hospital of Wisconsin and 60 cancer patients from the University of Alabama at Birmingham Hospital and the Children's Hospital of Alabama, also in Birmingham. The trial was the brainchild of Brian Hodgson, DDS, a pediatric dentist at Marquette University and Children's Hospital of Wisconsin – both in Milwaukee, Wis. Dr. Harry T. Whelan, Bleser Professor of Neurology at the Medical College of Wisconsin, served as the clinical trial principal investigator at Medical College of Wisconsin and Children's Hospital of Wisconsin. 


Patients participated in the multi-center, double-blind, placebo-controlled research study – a way of testing a medical therapy where some groups receive treatment and others receive a placebo treatment that is designed to have no real effect. Participants were randomly placed in one of four study groups: low- and high-risk patients receiving the experimental light therapy through the WARP 75 device, and other low- and high-risk patients receiving light through a similar device without therapeutic effects. The low-risk patients were those whose chemotherapy and radiation treatment tended to cause mild or no mucositis and the high-risk patients were those whose therapy treatment tended to cause severe cases of mucositis. 

Patients received the light therapy by a nurse holding the WARP 75 device -- about the size of an adult human hand – in close proximity to the outside of the patient's left and right cheek and neck area for 88 seconds each, daily for 14 days at the start of the patient's bone marrow or stem cell transplant. During that time, trained clinicians assessed the patient's mouth and patients completed a simple form to indicate their level of pain. 

"NASA is proud to be a part of the HEALS technology medical advancements that are improving the lives of cancer patients and providing new, innovative medical applications," said Helen Stinson, technical monitor for the NASA HEALS contract. "It's exciting to see the spinoffs from NASA's science and technology initiatives continually improve the quality of life for people here on Earth." 

The WARP 75 device is currently undergoing Food and Drug Administration premarket approval.

 


Original Source: https://www.nasa.gov/topics/nasalife/features/heals.html

Effect of NASA light-emitting diode irradiation on wound healing

Whelan HT1, Smits RL Jr, Buchman EV, Whelan NT, Turner SG, Margolis DA, Cevenini V, Stinson H, Ignatius R, Martin T, Cwiklinski J, Philippi AF, Graf WR, Hodgson B, Gould L, Kane M, Chen G, Caviness J. - J Clin Laser Med Surg. 2001 Dec;19(6):305-14. (Publication)
Study showed increases in growth of 155-171% of normal human epithelial cells and an improvment of greater than 40% in musculoskeletal training injuries in Navy SEAL
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OBJECTIVE:

The purpose of this study was to assess the effects of hyperbaric oxygen (HBO) and near-infrared light therapy on wound healing.

BACKGROUND DATA:

Light-emitting diodes (LED), originally developed for NASA plant growth experiments in space show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper, we review and present our new data of LED treatment on cells grown in culture, on ischemic and diabetic wounds in rat models, and on acute and chronic wounds in humans.

MATERIALS AND METHODS:

In vitro and in vivo (animal and human) studies utilized a variety of LED wavelength, power intensity, and energy density parameters to begin to identify conditions for each biological tissue that are optimal for biostimulation.

RESULTS:

LED produced in vitro increases of cell growth of 140-200% in mouse-derived fibroblasts, rat-derived osteoblasts, and rat-derived skeletal muscle cells, and increases in growth of 155-171% of normal human epithelial cells. Wound size decreased up to 36% in conjunction with HBO in ischemic rat models. LED produced improvement of greater than 40% in musculoskeletal training injuries in Navy SEAL team members, and decreased wound healing time in crew members aboard a U.S. Naval submarine. LED produced a 47% reduction in pain of children suffering from oral mucositis.

CONCLUSION:

We believe that the use of NASA LED for light therapy alone, and in conjunction with hyperbaric oxygen, will greatly enhance the natural wound healing process, and more quickly return the patient to a preinjury/illness level of activity. This work is supported and managed through the NASA Marshall Space Flight Center-SBIR Program.

Read more at: https://pdfs.semanticscholar.org/1f5b/0a4ce02a9c58dfd8531552fd2d2e2f3e701e.pdf

Original Source: https://www.ncbi.nlm.nih.gov/pubmed/11776448

“Quantum Leap” in Photobiomodulation Therapy Ushers in a New Generation of Light-Based Treatments for Cancer and Other Complex Diseases: Perspective and Mini-Review

Luis Santana-Blank, MD, Elizabeth Rodríguez-Santana, MD, Karin E. Santana-Rodríguez, BS, and Heberto Reyes, MD - Photomedicine and Laser Surgery (Publication)
A broad article, but follow the references located at the original document to learn more about more applicable topics.
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Abstract

Objective: Set within the context of the 2015 International Year of Light and Light-Based Technologies,and of a growing and aging world population with ever-rising healthcare needs, this perspective and mini-review focuses on photobiomodulation (PBM) therapy as an emerging, cost-effective, treatment option for cancer (i.e., solid tumors) and other complex diseases, particularly, of the eye (e.g., age-related macular degeneration, diabetic retinopathy, glaucoma, retinitis pigmentosa) and the central nervous system (e.g., Alzheimer's and Parkinson's disease). Background data: Over the last decades, primary and secondary mechanisms of PBM have been revealed. These include oxygen-dependent and oxygen-independent structural and functional action pathways. Signal and target characteristics determine biological outcome, which is optimal (or even positive) only within a given set of parameters. Methods: This study was a perspective and nonsystematic literature mini-review. Results: Studies support what we describe as a paradigm shift or “quantum leap” in the understanding and use of light and its interaction with water and other relevant photo-cceptors to restore physiologic function. Conclusions: Based on existing evidence, it is argued that PBM therapy can raise the standard of care and improve the quality of life of patients for a fraction of the cost of many current approaches. PBM therapy can, therefore,benefit large, vulnerable population groups, including the elderly and the poor, whilehaving a major impact on medical practice and public finances.

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Introduction

The United Nations declared 2015 to be the International Year of Light and Light-Based Technologies (IYL 2015) in recognition of the vital role of light-based systems in our daily lives, and their growing importance to meeting the world's challenges in areas as diverse as energy, education, telecommunication, agriculture, and health.1 Although our perception of light is often limited to the visible band of the electromagnetic (EM) spectrum,2 both lower and shorter wavelengths are increasingly used in new medical technologies3 including soft, injectable, and bioresorbable electronics.4 Described as an imperative cross-cutting discipline of in the twenty-first century, light science has already revolutionized the physical sciences and industry. The control of light at the nanoscale has unveiled a plethora of phenomena, leading to powerful new applications and setting high expectations for years to come.5 In particular, light's ability to control materials and transport coded signals forms the bases for many new photonic devices and systems, wherein photons act as tailor-made EM energy packets that can perform various functions.

Here, we describe a paradigm shift or “quantum leap” in the understanding and use of light and its interaction with water and other relevant photoacceptors to control biologic function in medicine through photobiomodulation (PBM) therapy. We propose that progress will lead to the imminent inception of PBM therapy as a mainstream treatment for multiple complex diseases, including solid tumors, as well as neurodegenerative diseases (NDs) of the eye and central nervous system (CNS)6–10 (Fig. 1). PBM therapy can raise the standard of care and improve the quality of life of patients at a fraction of the cost of many current approaches. Thus, a “quantum leap” in PBM therapy will benefit large and vulnerable population groups, including the elderly and the poor, while having a major impact on medical practice and public finances.11 This is particularly important because the high price of drug therapies, which can reach hundreds of thousands of dollars per year,12 as well as a growing and aging world population, are putting a severe strain on family and public finances around the world.13An external file that holds a picture, illustration, etc.
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FIG. 1.

Flow chart illustrating fields of light-based technologies, highlighting photobiomodulation (PBM) therapy applied to complex diseases as a quantum leap in medical therapeutics.

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Origin, Trajectory and Myriad Relationships in PBM's “Quantum Leap” in Medicine

Concurrent with progress in PBM therapy, a long history of discoveries has put medicine at the brink of a revolution in the use of light–water interactions for the treatment of complex diseases.7,8,10,14 Long ago, Albert Szent-Gyorgyi postulated that water was at the core of energy transfer in biological systems (i.e., quantum biology), and that that explained how energy from biomolecules could be translated into free energy for cells.15–17 Ling further elaborated on the physical state of water in living cells,18 and proposed on theoretical grounds that ordered layers of water could extend infinitely under ideal conditions.19,20Later, Huber proposed a structural basis of light energy and electron transfer in biology.21 More recently, Zewail and others showed that, with rapid laser techniques, it is possible to “see” how atoms in a molecule move during a chemical reaction.22 Light science has now reached microscales at the limit of recordable physical observation (e.g., resonant intermolecular transfer of vibrational energy in water at −100 fs)23,24showing, for example, the memory of persistent correlations in water structures within 50 fs, which is important in stabilizing biological systems.25 These and other tremendous achievements have changed our view of water, from a merely passive medium to an integral active player in the physiology of life, and have opened the gates to both direct measurement and control of physiological processes via light–water interaction.

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State of the Art in PBM

In 2016, PBM therapy will be added to the MeSH database as an entry term for records spanning five decades of research.26 As argued by Anders et al., this is a key step, as it distinguishes PBM therapy from light-based devices used for heating of tissues, such as near infrared (NIR) lamps or other applications that rely on thermal effects for all or part of their mechanisms of action.26 In contrast, PBM therapy employs low-level monochromatic or quasimonochromatic light, currently from visible blue (400 nm) to far-infrared (FIR 3200 nm), to induce nonthermal (≤0.01°C) photochemical and photophysical effects. Nonlinear processes through which PBM therapy can stimulate or inhibit; that is, modulate, physiological activity depend upon signal-to-noise rate and target cell/tissue parameters.27–29 Thus, signal and target characteristics determine biological outcome, which is optimal (or even positive) only within a narrow set of parameters.13

Over the last decades, primary and secondary mechanisms of PBM at the tissue, cellular, and molecular levels have been revealed. These include two major structural and functional action pathways. The first, or classic, action pathway relates to oxygen-dependent mechanisms operated by oxidation-reduction enzymes of the respiratory chain, particularly cytochrome c oxidase (CcO), which is partly responsible for light energy absorption and transfer to cells and tissues.30 This pathway is associated to cofactors, pigments, metals, and proteins that act as key redox centers within the body's bioenergetic rack mechanism described by Huber.21 Nitric oxide (NO), as a first-level player, also has an activation and modulation role in the oxygen-dependent pathway.31–33

The second, or oxygen-independent, action pathway centers on the vital role of water not only as the prevalent medium of life but as an active molecule, capable of absorbing radiant energy (e.g., IR light) and transporting/transducing it along extended biological surfaces, from bulk water to confined water in nanoscopic tissue and cell spaces. Light–water dynamics precede/coexist with the classic oxygen-dependent action pathway and complement and facilitate energy transfer for increased adenosine triphosphate (ATP) production.29,34,35 As a point of comparison, correlated internal electron- and proton-transfer reactions have been tracked in real time into the oxidized enzyme (CcO), revealing an overall real time of 3.46 ms.36 This relay is slower by several orders of magnitude than total energy transport through water dynamics from bulk liquid water to confined spaces.34

Oxygen-independent light–water interactions may further power and modulate molecular signaling pathways and gene transcription factors via multiple nonmetabolic pathways.10,35 For examle, the energy of the drive force wave of an infrared pulsed laser device (IPLD) used in our group's previous studies (NIR 0.27 eV) is within the range of the strength of hydrogen bonds,29,37 and the IPLD carrier wave oscillates at a frequency (3x 10e6 Hz) that enters in vibrational resonance with the rate of electron transfer through the DNA double helix.29,37 Theoretical evidence suggests that these wave properties promote the activation of open state dynamics,38,39 allowing the activation of complex chaotic dynamics as well as the regulation of DNA replication and transcription, because the existence of open states in one place of the chain can influence the dynamics of other distant open states.29,34,35 Resulting effects match reported reductions in the frequency of chromosome aberrations induced by that low-energy laser irradiation,40 as well as theoretical,38,39 experimental,27,28 and clinical studies.41–48 These and other oxygen-independent PBM effects are channeled through metabolic control levels to regulate the energy-dependent path from the genotype to the phenotype.49,50

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Light–Water Interactions and the Quantum Leap in PBM

We propose that the key to understanding and controlling the biophysics and biochemistry of higher-order organisms stems from their dual aqueous and energy-dependent nature. Water represents 70% by mass of an adult human body, or nearly 99% of total molecules by number, given water's low molecular weight. In addition, high-order organisms, including humans, can be represented as complex electrochemical (semiconducting) systems that comprise a vast array of energy-sensitive materials and machinery, such as ion pumps (e.g., chemically driven electron pumping through molecular wires, such as the D pathway in CcO),34 molecular motors (e.g., ATP synthase and Brownian biomotors), transistors-capacitors (e.g., cell membrane), liquid crystals (e.g., membrane structure), and rechargeable electrolytic biological batteries (e.g., hydrophilic interface in cells/tissues). Life system's double nature, whose two main structural and functional pillars are energy and water joined to biomolecules, has, therefore, tremendous consequences for life and health.

Water's permittivity, calculated considering the system as a plane capacitor, is generally high. Therefore, radiant energy can penetrate and be absorbed by tissues to provide powerful tools in medicine.51 One example is the exclusion zone (EZ) described by Pollack.52 High-energy EZ water forms along hydrophilic surfaces (e.g., tissue interfaces) in response to radiant energy.53 Remarkably, EZ water can separate and store electrical charges, and can release up to 70% of such charges when it is perturbed, such as by injury-induced redox potentials.54 We have argued that supplied energy can power and modulate cellular work and signaling pathways, even when the metabolic energy pathway has been compromised, steering cells toward or away from programmed cell death.34 EZ water may, thus, act as an electrolytic bio-battery,35 which can efficiently and selectively transfer energy to sites expressing redox injury potentials, as found in cancer and other complex diseases, triggering reparative and regenerative mechanisms that can lead to restoring homeostasis/homeokinesis and, ultimately, health.29,34,35

Experimentally, IR energy absorption by water has been recently modeled in a porcine model, confirming that absorption depends upon fluence and wavelength. Further, the higher the concentration of water in tissues, the higher IR energy absorption will be.55 This is consistent with controlled clinical studies in solid tumors and complex ophthalmic and neurologic diseases,9,46,56 as well as molecular, biochemical, biophysical, and metabolic mechanistic support for a quantum leap in medical therapeutics based on the simple, but powerful, idea that properly tailored light can power and modulate physiologically reparative mechanisms.30,57–62

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Cancer and Tumor Microenvironments

The bases of our understanding of cancer are constantly being questioned and revised, leading to new treatment goals. In a paradigm-changing editorial, Prendergast recently argued that “disorders in microenvironment and peripheral systems that control cancer might increasingly be viewed as primary rather than secondary factors in the root nature of cancer as a clinical disease.” This constitutes “a crucial and radical distinction from prevailing thought, since it implies that cancer may be a symptom of an underlying clinical disorder, rather than the root problem itself that needs to be addressed.” 6,63

Prendergast further suggested that “effective treatment of cancer may not necessarily entail understanding or addressing this complexity, but mastering the use of tissue or systemic systems that have the inherent ability to do so.” Hence, a common thread linking emerging perspectives in oncology and PBM therapy may well be the restitution of tissue homeostasis-homeokinesis via light-energy supplementation, a microenvironment effect that comprises and extends the Warburg effect previously discussed by our group.57,64–67

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Photobiomodulation and Cancer

As far back as 1964–1966, McGuff et al. showed 64,65 that “laser energy has a selective effect on certain malignant tumors, resulting in their progressive regression and ultimate dissolution.” Following years of controversy,66,67 editorials by Karu68 and Lanzafame11,69 now stress evidence supporting the potential anticancer effects of PBM.11,68,69 New data confirm that PBM under certain parameters is safe for use in cancer patients.60 This is in accord with clinical results from our group using the abovementioned proof of concept IPLD.4,44

A phase I trial in patients with advanced neoplasias demonstrated that the IPLD studied was safe for clinical use and improved performance status and quality of life.41 Antitumor activity was observed in 88.23% of patients with 10 years of follow-up.41

In that series, T2-weighted MRI data showed increased water content of tumor heterogeneities42,44 preceding tumor-volume reduction and a therapeutic anticancer effect.42,44 Structural, kinetic, and thermodynamic implications of these changes in water dynamics have been analyzed at the tissue, cell, and interstitial levels.27 In conjunction, selective activation of programmed cellular death [i.e., apoptosis, necrosis, and anoikis (cell death by loss of cell adhesion)] and cytomorphologic modification (e.g., reduced size, increased roundness, increased vacuoles) were documented in neoplastic cells, but not in peripheral tissues.8,42 Modulation of cluster of differentiation (CD)4 CD45RA+, CD25 activated, tumor necrosis factor alpha (TNF-α), and soluble interleukin (IL)-2 receptor (sIL-2R) was further documented.43These hallmark results, supported by independent data,70–72 demonstrate that PBM therapy can modulate antitumor effects,6,8 in sharp contrast with long-held views.45,73,74 This evidence is also consistent with growing experimental and clinical reports from multiple other authors.60,75–82

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PBM and Ophthalmic and Neurodegenerative Disorders

Recent evidence underscores common mechanisms between cancer and NDs of the eye and CNS. Research suggests that oxidative proteome damage may be the most likely cause of aging and age-related maladies such as cancer and other complex diseases, including NDs.83 Findings also show “common mechanisms of onset,” with a focus on genes such as DJ-1 and Myc-Modulator 1 (MM-1) and signaling pathways that contribute to the onset and pathogenesis of cancer and NDs such as retinitis pigmentosa (RP), Parkinson disease (PD), and cerebellar atrophy.”84 Finally, both disease groups are profoundly energetic in nature, featuring prominent deterioration of metabolic energy pathways.10

External light energy supplementation has been shown to generate neuroprotective, vasoprotective, baroprotective, immunomodulatory, and regenerative effects (Fig. 2). 47 We have documented that such effects may be activated and modulated locally and/or remotely via oxygen-dependent and oxygen-independent pathways that can encompass extended biologic surfaces and may even reach avascular eye tissues (i.e., cornea, lens, aqueous humor, and vitreous) noninvasively. Although a full elucidation of involved mechanisms escapes the scope of this perspective and mini-review, a very brief discussion of results from multiple authors is given subsequently.

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FIG. 2.

Electromagnetic (light) energy supplementation based on water–light interactions. Upper left side shows classic oxygen (O2) dependent pathways by which light energy generates adenosine triphosphate (ATP)/ guanosine-5′-triphosphate (GTP) and other high-energy molecules. Upper right side shows O2 independent pathways by which photoinduced, nonlinear, oscillations in water provide energy for cellular work, signaling, and gene transcription. Top center shows interfacial exclusion zone (EZ) water, which acts as a selective rechargeable electrolytic bio-battery. Together, these pathways activate and modulate physiologically reparative mechanisms which, at appropriate irradiation parameters, can generate neuroprotective, vasoprotective, baroprotective, immunomodulator, and regenerative effects locally and remotely, promoting homeostasis/homeokinesis through the coupling and synchronization of biophysical, biochemical, biomechanical, and hydrodynamic oscillators, as guided by the second law of thermodynamics. Arrows point to the sequence and direction of events. (Updated from reference 47. Authors retained copyright.)

PBM has shown promise in the treatment of diabetic retinopathy (DR),85,86 age-related macular degeneration (AMD),46 glaucoma,47 RP,87 Stargardt disease,88 Leber's hereditary optic neuropathy,89 Alzheimer's disease (AD), and PD, 90,91 among other conditions.89 Strikingly, although each of these NDs has different etiologies and pathogeneses, “they frequently induce a set of cell signals that lead to well-established and similar morphological and functional changes, including programmed cell death. Furthermore, oxidative stress, activation of apoptotic pathways and inflammatory response, are common features in all these diseases.”92

 

Remarkably, PBM can modulate apoptosis as well as necrosis.42,45,47 PBM can also be both pro-oxidant in the short term, but antioxidant in the long term,93 thus modulating reactive oxygen species (ROS) generation. We also found clinical evidence of immune regulatory effects over inflammation during treatment of solid tumors with the IPLD, a NIR diode laser pulsed at a frequency of 3 MHz.43 These results are in agreement with the regulating role of the vagal reflex on the inflammatory reflex reported by Tracey, using an electronic device that stimulated nerves to treat inflammation.71,72

In addition, PBM has been shown to protect against retinal dysfunction and photoreceptor cell death in rodent models of retinal injury and retinal degeneration.94 PBM has been further reported to attenuate oxidative stress and inflammation in primary astrocytes induced by amyloid β peptide (Aβ),95 and to reduce Aβ-induced apoptosis,96 which is thought to play a major role in AD. Nevertheless, it has been argued that red to NIR light cannot be transmitted through the scalp to the brain more than a few centimeters,97 which makes it nearly impossible to noninvasively treat AD with PBM 98 using conventional (direct) delivery systems/methods. Similarly, although an absence of adverse effects from 670 and 830 nm PBM applied to the retina in Sprague Dawley albino rats has been reported,94 extreme care must be taken to avoid photodamage of the eye99 from direct PBM procedures.

Conversely, we published an interventional case report of a patient with bilateral geographic atrophic AMD (gaAMD) and associated neurologic disease treated noninvasively, indirectly, and at a distance (i.e., remotely) from ocular structures and the CNS with the above-referenced IPLD/photo-infrared pulsed bio-modulation (PIPBM).46 Results showed neurologic improvement, transitory color vision, enhanced visual acuity, full-field electroretinogram (ERG) modifications toward a normal rhythm, drusen mobilization, decreased lens opacity, and lower intraocular pressure (IOP), in accord with a retrospective noncomparative data analysis from the phase I trial of patients with advanced cancer treated with the IPLD,41 which showed statistically significant evidence of a therapeutic hypotensor effect over IOP,47 and they are consistent with the positive neurological evolution of two trial patients.

Moreover, although trial participants did not develop media opacity, one pre-existing incipient cataract in the right eye of a patient (transitional meningioma) became denser and slightly smaller 3 months post-treatment, and remained unchanged 1 year post-treatment. The left eye lens of the same patient was unaffected. Although the finding could be part of the natural history of the cataract, we stressed that possible deterministic effects related to the initial metabolic or biochemical state of lens opacities should be studied.41

In accordance with the what was described, a robust body of evidence suggests that protein misfolding, insolubility, and aggregation are at the root of both cataracts and other diseases including AD, PD, and Huntington's disease,100 and that external EM energy (light) supplementation can have reparative effect on protein misfolding, activating and modulating metabolic control levels of protein folding/unfolding.10,34In addition, PBM effects on targets such as heat shock proteins (α crystalline), enzymes of the antioxidative system, Na+-K+-ATPase, Ca +2-ATPase, aquaporins (AQPs), and ion pumps have been referred to as part of mechanisms that could have influenced the response observed in the lens on the cases studied.46 We further proposed that, among other effects, PBM can stimulate and/or substitute ATP production via water dynamics, which is vital for the activation and inactivation kinetics in phototransduction.46 PBM can also affect the synthesis of molecules in a liquid crystalline (LC) state (e.g., self-assembly of lipids, water, and other biomolecules such as proteins and sterols, which are sensitive to temperature and/or electric fields) If confirmed, the latter may have multidisciplinary applications in medicine and biology in areas such as photovision, in which LCs are essential functional components.28

A first rapid communication referring to the retina and optic nerve additionally showed first evidence of EZ water as a selective rechargeable bio-battery applicable to PBM, suggesting a new understanding of the eye's energetic environment, which may have deep implications in ocular physiology as well as in the pathophysiology, diagnosis, and treatment of blinding diseases using light-based therapies.48 Therefore, as a promising alternative to drug therapies,101 or in combination with other treatments, PBM therapy may be developed into a viable therapeutic approach with multidisciplinary applications in ophthalmology and neuroscience,46 inducing and modulating physiologically reparative and regenerative effects that can favor homeostasis/homeokinesis27–29 through the coupling and synchronization of biophysical, biochemical, biomechanical, and hydrodynamic oscillators, as guided by thermodynamics.

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Treatment Costs and Availability

At the 2015 American Society of Clinical Oncology (ASCO) annual meeting, Dr. Leonard Saltz, chief of gastrointestinal oncology at Memorial Sloan Kettering Cancer Center, discussed the high cost of cancer drugs. He argued that “the unsustainably high prices of cancer drugs is a big problem, and it's our problem,” citing as examples the cost of nivolumab ($28.78/mg) and ipilimumab ($157.46/mg), which is “approximately 4000 times the cost of gold.”102 Previously, >100 oncologists had protested the high price of cancer drugs, also calling them economically “unsustainable.” They noted that, of 12 cancer drugs approved in 2012, 11 were priced > $100,000 per year,103 with multiple drugs often being required for extended periods. Such high prices and their impact on families, governments, and society at large are leading some to propose that cost should be considered a “financial toxicity” to be assessed with other toxicities when treatments are considered by doctors and patients.104 In contrast, although it has been estimated the cost of developing new drug therapies can run up to USD $1.3–$1.7 billion,105,106 the development cost of new photonics devices can be substantially lower, which can lower therapy costs and increase treatment availability. For the same reasons, PBM can also offer a noninvasive and cost-effective therapeutic option for patients with NDs of the retina, brain, and beyond.5685

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Conclusions

The celebration of the IYL 2015 by the United Nations1 is a fitting time to announce what we describe here as a “quantum leap” in PBM therapy. It is also a good opportunity to ensure that policy makers and the medical community become aware of and embrace the immense potential of light-based medical technologies, especially PBM therapy, as an emerging treatment option for cancer and other complex diseases.107 Although not all tissues respond to PBM therapy,69 in vitro and in vivo xenografts and evidence from clinical studies does suggest that it is time to begin considering PBM therapy as a potential drug equivalent.11,108 In addition, PBM therapy may have minimal or no adverse effects, improve quality of life and functional status and raise the current standard of care for many cancer patients when used alone or in combination with other therapies.9 PBM therapy further represents a novel hope for the treatment of numerous eye and neurologic diseases. And as stated, PBM may be developed at a lower cost than many current treatments,8,10 which can help meet the healthcare needs of an increasing and aging world population. As such, this perspective and mini-review focuses on the large potential tangible contributions of light-based therapies for large demographic segments of the population, such as aging “baby boomers” who are expected to face a higher incidence of diseases such as cancer, AMD, DR, glaucoma, RP, AD, and PD, as well as other neurologic diseases in the next 15 years. In light of the growing costs of drugs and their impact on developed and developing countries, we propose that PBM therapy may offer a novel, safe, and effective therapy choice that would be more accessible to large vulnerable groups, such as the poor and the elderly.

Concurrently with the United Nations' declaration of 2015 as the year of light and light-based technologies, PBM therapy stands at the brink of delivering a new generation of treatments for complex diseases. New PBM therapies will preserve quality of life and raise standard of care in an efficient and cost-efficient manner. This will particularly benefit the most vulnerable demographic sectors, such as the elderly and the poor, and reduce the strain of growing healthcare costs in both industrialized and developing countries. We propose that such developments and their imminent impact represent a paradigm shift or “quantum leap” in PBM therapy and medicine at large.

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Acknowledgments

We thank Jesús Alberto Santana-Rodríguez for reviewing and editing this article, and Luis Rafael Santana-Rodríguez for design and technical support. This study was supported by Fundalas, Foundation for Interdisciplinary Research and Development.

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Author Disclosure Statement

No competing financial interests exist.

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References

 


Original Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4782038/

Performance Chiropractic and Wellness: The Complete A-Z Manual for Low Level Laser Therapy 5th edition

Jerome Rerucha B.S., C.S.C.S., D.C. - 2015 (Book)
Dr Rerucha is on the cutting edge at documenting how different pulsing frequencies can be used for different stilulatory effects. He works mainly with Erchonia.
View Resource

The Biological Basics of Low Level Laser Light Therapy

  • summary
  • introduction
  • Alexander Gurwitsch: cells emit light
  • non-linear dynamics
  • introducing quantum physics
  • itroduction to quantum biology
  • quantum coherence in biology
  • biological coherence and the sensitivity of living systems
  • Fritz Albert Popp: biophotons
  • Guenther Albreecht-Buehler: cells respont to light
  • Mae-Wan Ho: visualizing coherence
  • conclusions

Therapeutic Laser Applications

  • how does low level laser therapy work?
  • what are the advantages over other modes of therapy?
  • cliniclal use of low level laser therapy
  • abstract submitted to laser and surgury medicine
    • background and objective
    • methods
    • results
    • conclusion
    • safety considerations
    • eye considerations
    • pace makers and other implanted devices
    • pregnancy
    • excessive toxicity
    • preface to treatment section

Nerver Roots

  • flexion and extension
  • lateral flexion
  • rotation
  • MRT (muscle response testing) through ROM of cervical spine
  • shoulder
  • neurological level
    • C5
    • C6
    • C7
    • C8
    • T1
    • S1
    • L5
    • L4
    • L3
    • L3-L5
    • L2-L4
    • L1-L3
  • low back

Top Ten Laser Protocols

  • organ / glands / tissue
  • acute injury (shock)
  • pain
  • lymphatic protocol
  • detox protocol
  • immune protocol
  • hormone protocol
  • basic cranial nerve
  • tissue memory
  • trauma preparation protocol

A-Z Laser Protocols

  • abdominal cramping
  • abdominal inflammation/pain
  • abrasions
  • abscess
  • achilles tear / strain (partial only; not rupture)
  • acidosis (hyperacidity
  • acid reflux
  • acne
  • acute injury
  • adenoids
  • (ADD) atention deficit disorder and hyperactivity disorder (ADHD)
  • Addiction
  • addison's disease
  • adhesions
  • adhesive capsulitis
  • adrenal
  • aids
  • allergies
  • alopecia
  • alpha waves
  • alzheimer's
  • amenorrhea
  • amoebas
  • amyotrophic lateral sclerosis / lou gehrig's disease / motor neuron
  • amnesia
  • anemia
  • anger
  • angina
  • anosmia (loss of smell)
  • anxiety appendicitis
  • arrhythmias
  • arteries / arteriosclerosis
  • arthritis
  • asthma
  • ataxia
  • athlete's foot
  • atrophy
  • backache / back pain
  • bacteria
  • bed sores
  • bedwetting
  • bell's palsy
  • beta waves
  • bites
  • bladder
  • bleeding gums
  • bloating
  • blood pressure (high)
  • blood pressure (low)
  • blood sugar balance
  • boils
  • bone
  • bowel
  • bradycardia
  • brain
  • breast augmentation
  • bronchitis
  • bruises
  • buerger's disease
  • bunions
  • burns
  • burns (second degree)
  • bursitis
  • calcium deposits or formations
  • candida
  • canker sores
  • capsulitis
  • carpal tunnel syndrome
  • cartilage
  • cataracts
  • chemical peels / resurfacing
  • chest pain
  • chicken pox (herpes zoster / varicella)
  • cholecystitis
  • cholelithiasis
  • chronic fatigue
  • chronic pain
  • circulation
  • cirrhosis
  • cold sores (herpes simplex 1)
  • colds and flu
  • colitis
  • concussion
  • confusion
  • congestion
  • congestive heart falure (CHF)
  • conjunctivitis (pink eye)
  • costipation
  • cramps (muscle)
  • cranial nerves (general)
  • cranial nerves VIII
  • crepitus
  • crohn's disease
  • cuts
  • cushing's syndrome
  • cytomegalovirus (herpes syndrome V)
  • deer tick
  • delta waves
  • depression
  • dermatitis
  • detoxification
  •  diabetes
  • diabetic neuropathy
  • diabetic ulcers
  • digestion
  • dim vision
  • disc herniation
  • dizziness
  • dupuytren's contracture
  • dyslexia
  • ear ache
  • ear infection
  • eczema
  • edema
  • emotional stress
  • emphysema
  • emulsification of fat
  • endometriosis
  • epistaxis
  • epstein - barr virus
  • esophagitis
  • exercise recovery
  • eye conditions
  • facet syndrome
  • facial paralysis
  • fever
  • fever blisters
  • fibromyalgia
  • flu
  • food intolerance
  • food poisoning
  • foot fungus
  • fracture
  • fungus
  • gait
  • gallbladder (general)
  • gallbladder (stones)
  • ganglion cyst
  • general musculoskeletal
  • gerd
  • gingivitis
  • glaucoma
  • goiter
  • gout
  • gums
  • headache
  • heart
  • heartburn
  • hearing difficulty
  • hemorrhoids
  • hepatitis A
  • hepatitis B
  • hepatitis C
  • hernia
  • herpes simplex
  • herpes zoster (chickenpox / varicella)
  • HIV
  • hives
  • hoarseness
  • hormone balance
  • hot flashes
  • human papilloma virus (HPV)
  • hyperactivity
  • hyper/hypo-tension
  • hyper/hypo-thyroid
  • hyper/hypo-gycemia
  • impotence
  • immune enhancement
  • incontinence
  • indigestion
  • infection
  • inflammatory bowel disease
  • inflammation
  • influenza
  • injuries
  • insect bites
  • irritable bowel syndrome
  • ischemia
  • jaundice
  • joints
  • keloid
  • kidney
  • kidey stones
  • large intestine
  • laryngitis
  • ligament
  • liposuction
  • liver (balace and support)
  • loss of smell (anosmia)
  • loss of taste
  • low back pain
  • lungs
  • lyme disease
  • lymphadentis
  • lymphatic
  • macular degeneration
  • memory problems
  • meniere's disease
  • meniscus sprain (grade 1)
  • menopause
  • mensturation
  • mental fatigue
  • meridian balance 15
  • migraine
  • motion sickness
  • multiple sclerosis
  • muscle
  • muscle spasm
  • myocardial inrarction
  • nerve root
  • neurogenic inflammation
  • neuropathy
  • nervousness
  • nose bleed
  • numbness
  • nystagmus
  • ocular motility disorders
  • ocular nerve
  • olfactory nerve
  • osgood-schlatter disease
  • otitis
  • pain
  • pain (chronic)
  • pain (general)
  • injury related pain (localized)
  • pain (acute injury)
  • pancreas
  • parasite
  • parasympathetic facilitazation
  • paresthesia (numbness)
  • periodontal disease
  • pink eye (conjunctivitis)
  • plantar fasciitis
  • pneumonia
  • polycystic kidney diseases
  • polycystic ovary
  • post operative scar revision
  • post operative wound healing / pain
  • post traumatic stress disorder (PTSD)
  • postnasal drip
  • premenstral syndrome (PMS)
  • pre set head PL-touch
  • pre-op
  • prostate
  • psoriasis
  • punctures
  • rash
  • reflex sympathetic dystrophy (RSD)
  • renal problems
  • respiratory problems
  • restless leg syndrome
  • retinitis pigmentosa
  • rheumatism
  • ringworm
  • road rash
  • scar tissue
  • sciatica
  • sedation
  • seizures
  • shingles
  • sinusitis
  • skin
  • sleep apnea
  • small intesine
  • smell - lack of
  • sore throat
  • soreness
  • spasm
  • spider veins
  • spleen
  • sprains
  • spurs
  • standars (neurological) setting
  • stanard (up-regulation) setting
  • staph infection
  • stings
  • stomach ulcer
  • strep infections
  • stress
  • stroke
  • sty
  • subluxation
  • sunburns
  • swimmer's ear
  • swollen ankles
  • sympathetic calming
  • tachycardia
  • taste - lack of
  • teeth
  • tendonmyopathy (tendonitis)
  • tension headaches
  • theta waves
  • thoratic outlet syndrome
  • throat
  • thrush
  • thyroid (hyper)
  • thyroid (hypo)
  • tinnitus
  • TMJ
  • toenail fungus
  • tonsilitis
  • toothache
  • ulcer
  • ulcerative colotis
  • up-regulation
  • urinary tract infection
  • varicose veins
  • veins
  • venereal warts
  • viral infections
  • voice
  • vomiting
  • water retention
  • watery discharge from eye
  • warts
  • wounds
  • yeast

Original Source: http://www.coldlasers.org/lllt-books/

Mechanisms and applications of the anti-inflammatory effects of photobiomodulation

Michael R Hamblin - PMC 2017 Jul 24 (Publication)
Chronic diseases of the modern age involving systemic inflammation such as type II diabetes, obesity, Alzheimer's disease, cardiovascular disease and endothelial dysfunction are again worth investigating in the context of PBM.
View Resource

Abstract

Photobiomodulation (PBM) also known as low-level level laser therapy is the use of red and near-infrared light to stimulate healing, relieve pain, and reduce inflammation. The primary chromophores have been identified as cytochrome c oxidase in mitochondria, and calcium ion channels (possibly mediated by light absorption by opsins). Secondary effects of photon absorption include increases in ATP, a brief burst of reactive oxygen species, an increase in nitric oxide, and modulation of calcium levels. Tertiary effects include activation of a wide range of transcription factors leading to improved cell survival, increased proliferation and migration, and new protein synthesis. There is a pronounced biphasic dose response whereby low levels of light have stimulating effects, while high levels of light have inhibitory effects. It has been found that PBM can produce ROS in normal cells, but when used in oxidatively stressed cells or in animal models of disease, ROS levels are lowered. PBM is able to up-regulate anti-oxidant defenses and reduce oxidative stress. It was shown that PBM can activate NF-kB in normal quiescent cells, however in activated inflammatory cells, inflammatory markers were decreased. One of the most reproducible effects of PBM is an overall reduction in inflammation, which is particularly important for disorders of the joints, traumatic injuries, lung disorders, and in the brain. PBM has been shown to reduce markers of M1 phenotype in activated macrophages. Many reports have shown reductions in reactive nitrogen species and prostaglandins in various animal models. PBM can reduce inflammation in the brain, abdominal fat, wounds, lungs, spinal cord.

2.1. Cytochrome c oxidase in mitochondria

Cytochrome c oxidase (CCO) is unit IV in the mitochondrial electron transport chain. It transfers one electron (from each of four cytochrome c molecules), to a single oxygen molecule, producing two molecules of water. At the same time the four protons required, are translocated across the mitochondrial membrane, producing a proton gradient that the ATP synthase enzyme needs to synthesize ATP. CCO has two heme centers (a and a3) and two copper centers (CuA and CuB). Each of these metal centers can exist in an oxidized or a reduced state, and these have different absorption spectra, meaning CCO can absorb light well into the NIR region (up to 950 nm) [9]. Tiina Karu from Russia was the first to suggest [10,11], that the action spectrum of PBM effects matched the absorption spectrum of CCO, and this observation was confirmed by Wong-Riley et al in Wisconsin [12]. The assumption that CCO is a main target of PBM also explains the wide use of red/NIR wavelengths as these longer wavelengths have much better tissue penetration than say blue or green light which are better absorbed by hemoglobin. The most popular theory to explain exactly why photon absorption by CCO could led to increase of the enzyme activity, increased oxygen consumption, and increased ATP production is based on photodissociation of inhibitory nitric oxide (NO) [13]. Since NO is non-covalently bound to the heme and Cu centers and competitively blocks oxygen at a ratio of 1:10, a relatively low energy photon can kick out the NO and allow a lot of respiration to take place [14].

2.2. Light gated ion channels and opsins

More recently it has become apparent that another class of photoreceptors, must be involved in transducing cellular signals, particularly responding to blue and green light. Thee photoreceptors have been proposed to be members of the family of light-sensitive G-protein coupled receptors known as opsins (OPN). Opsins function by photoisomerization of a cis-retinal co-factor leading to a conformational change in the protein. The most well known opsin is rhodopsin (OPN1), which is responsible for mediating vision in the rod and cone photoreceptor cells in the mammalian retina. There are other members of the opsin family (OPN2-5), which are expressed in many other tissues of the body including the brain [15]. One of the best-defined signaling events that occurs after light-activation of opsins, is the opening of light-gated ion channels such as members of the transient receptor potential (TRP) family of calcium channels [16]. TRP channels are now known to be pleiotropic cellular sensors mediating the response to a wide range of external stimuli (heat, cold, pressure, taste, smell), and involved in many different cellular processes [17]. Activation of TRP causes non-selective permeabilization (mainly of the plasma membrane) to calcium, sodium and magnesium [18]. It is now known that TRP channel proteins are conserved throughout evolution and are found in most organisms, tissues, and cell-types. The TRP channel superfamily is now classified into seven related subfamilies: TRPC, TRPM, TRPV, TRPA, TRPP, TRPML, and TRPN [19]. Light-sensitive ion channels are based on an opsin chromophore (isomerization of a cis-retinal molecule to the trans configuration) as illustrated in Drusophila photoreceptors [20].

We have shown that blue or green light (but not red or 810 nm NIR) increased intracellular calcium in adipose derived stem cells, that could be blocked by ion channel inhibitors [5].

2.3. Flavins and flavoproteins

There is another well-known family of biological chromophores called cryptochromes. These proteins have some sequence similarity to photolyases [21], which are blue light responsive enzymes that repair DNA damage in bacteria caused by UV exposure [22]. Cryptochromes rely on a flavin (flavin adenine dinucleotide, FAD) or a pterin (5,10-methenyltetrahydrofolic acid) to actually absorb the light (again usually blue or green). Cryptochromes have been studied mainly in plants and insects. Recent evidence has emerged that mammalian cryptochromes are important in regulation of the circadian clock. It is thought that human cryptochromes (CRY1 and CRY2) send signals via part of the optic nerve to the suprachiasmatic nucleus (SCN) in the brain, which is the master regulator of the CLOCK system to entrain biological responses to the light-dark cycle [23]. However the situation is complicated because retinal ganglion cells containing melanopsin (OPN4) are also involved in photoentrainment [24]. Studies are still ongoing to investigate this redundancy [25].

It should be emphasized that compared to CCO and mitochondria, evidence is still emerging concerning the extent to which opsins, cryptochomes and light-gated ion channels (which may be widely expressed in many different cell types) could be responsible for PBM effects. If their role is significant it is likely to be in the blue and green spectral regions. Further research will be necessary to explore their role in anti-inflammatory effects, wound healing and tissue regeneration.

2.4. Water as a chromophore and heat-gated ion channels

Since the biological effects of light continue to be observed, as the wavelength increases in the infra-red region (>1000 nm), beyond those known to be absorbed by CCO, it is now thought likely that an alternative chromophore must be responsible. The obvious candidate for this alternative chromophore is water molecules whose absorption spectrum has peaks at 980 nm, and also at most wavelengths longer than 1200 nm. Moreover, water is by the far the most prevalent molecule in biological tissue (particularly considering its low molecule weight = 18). At present the proposed mechanism involves selective absorption of IR photons by structured water layers (also known as interfacial water) [26] or water clusters [27], at power levels that are insufficient to cause any detectable bulk-heating of the tissue. A small increase in vibrational energy by a water cluster formed in or on a sensitive protein such as a heat-gated ion channel, could be sufficient to perturb the tertiary protein structure thus opening the channel and allowing modulation of intracellular calcium levels [28]. Pollack has shown that interfacial water can undergo charge separation when it absorbs visible or NIR light [29]. This charge separation (equivalent to localized pH changes) could affect the conformation of proteins [30]. It has also been suggested that PBM could reduce the viscosity of interfacial water within the mitochondria, and allow the F0F1 ATP synthase, which rotates as a nanomotor to turn faster [31]. It should be noted here that the first regulatory approvals of PBM were gained as a 510 K device “equivalent to an non-heating IR lamp” [32]. While the involvement of water as a chromophore may still be considered hypothetical it is difficult to think of another explanation for the beneficial of PBM at wavelengths between 1000 nm all the way to 10,000 nm (carbon dioxide laser).

3.1. PBM increases ROS in normal cells

When PBM stimulates CCO activity in normal healthy cells, the resulting increase in mitochondrial membrane potential (MMP) above normal baseline levels, leads to a brief and rather modest increase in generation of reactive oxygen species (ROS) [33]. However this brief burst of ROS caused by 3 J/cm2 of 810 nm laser (Figure 2A) was shown to be sufficient to activate the redox-sensitive transcription factor, NF-kB in embryonic fibroblasts [34] (Figure 2B). Addition of the anti-oxidant N-acetyl-cysteine to the cells could block the NK-kB activation (Figure 2C), but not the increase in cellular ATP caused by the mitochondrial stimulation (Figure 2D). In primary cultured cortical neurons [35], 810 nm laser produced a biphasic dose response in ATP production (Figure 3A) and MMP (Figure 3B) with a maximum at 3 J/cm2. At a high dose (30 J/cm2) the MMP was actually lowered below baseline. Interestingly the dose-response curve between fluence (J/cm2) and ROS production showed two different maxima (Figure 3C). One of these maxima occurred at 3 J/cm2 where the MMP showed its maximum increase. The second maximum in ROS production occurred at 30 J/cm2 where the MMP had been reduced below baseline. At a value between these two fluences (10 J/cm2) a dose at which the MMP was approximately back to baseline, there was not much ROS generation. These data are very good examples of the “biphasic dose response” or “Arndt-Schulz curve” which is often discussed in the PBM literature [7,8].

Thus it appears that ROS can be generated within mitochondria when the MMP is increased above normal values and also when it is decreased below normal values. It remains to be seen whether these two kinds of PBM-generated ROS are identical or not. One intriguing possibility is that whether the ROS generated by PBM is beneficial or detrimental may depend on the rate at which it is generated. If superoxide is generated in mitochondria at a rate that allows superoxide dismutase (SOD) to detoxify it to hydrogen peroxide, then the uncharged H2O2 can diffuse out of the mitochondria to activate beneficial signaling pathways, while if superoxide is generated at a rate or at levels beyond the ability of SOD to deal with it, then the charged superoxide may build up inside mitochondria and damage them.

3.2. PBM reduces ROS in oxidative stressed cells and tissues

Notwithstanding, the ability of PBM to produce a burst of ROS in normal cells, it is well-accepted that PBM when as a treatment for tissue injury or muscle damage is able to reduce markers of oxidative stress [36,37,38]. How can these apparently contradictory findings be reconciled? A study attempted to answer this question [39]. Primary cultured cortical neurons were treated with one of three different interventions, all of which were chosen from literature methods of artificially inducing oxidative stress in cell culture. The first was cobalt chloride (CoCl2), which is used as a mimetic for hypoxia and works by a Fenton reaction producing hydroxyl radicals [40]. The second was direct treatment with hydrogen peroxide. The third was treatment with the mitochondrial complex I inhibitor, rotenone [41]. All three of these different treatments increased the intracellular mitochondrial ROS as judged by Cell-Rox Red (Figure 4A), and at the same time lowered the MMP as measured by tetramethyl-rhodamine methyl ester (TMRM) (Figure 4B). PBM (3 J/cm2 of 810 nm laser) raised the MMP back towards baseline, while simultaneously reducing the generation of ROS in oxidatively stressed cells (while slightly increasing ROS in normal cells). In control cells (no oxidative stress), PBM increased MMP above baseline and still produced a modest increase in ROS.

Since most laboratory studies of PBM as a therapy have looked at various animal models of disease or injury, it is not surprising that most workers have measured reduction in tissue markers of oxidative stress (TBARS) after PBM [36,42]. There have been a lot of studies looking at muscles. In humans, especially in athletes, high-level exercise produces effects in muscles characterized by delayed-onset muscle soreness, markers of muscle damage (creatine kinase), inflammation and oxidative stress.

One cellular study by Macedo et al [43] used muscle cells isolated from muscular dystrophy mice (mdx LA 24) and found that 5 J/cm2 of 830 nm increased the expression levels of myosin heavy chain, and intracellular [Ca2+]i. PBM decreased H2O2 production and 4-HNE levels and also GSH levels and GR and SOD activities. The mdx cells showed significant increase in the TNF-α and NFκB levels, which were reduced by PBM.

While it is highly likely that the effects of PBM in modulating ROS are involved in the anti-inflammatory effects of PBM, it would be dangerous to conclude that that is the only explanation. Other signaling pathways (nitric oxide, cyclic AMP, calcium) are also likely to be involved in reduction of inflammation.

As mentioned above we found [34] that PBM (3 J/cm2 of 810 nm laser) activated NF-kB in embryonic fibroblasts isolated from mice that had been genetically engineered to express firefly luciferase under control of an NF-kB promoter. Although it is well-known that NF-kB functions as a pro-inflammatory transcription factor, but on the other hand it is also well known that in clinical practice or in laboratory animal studies) PBM has a profound anti-inflammatory effect in vivo. This gives rise to another apparent contradiction that must be satisfactorily resolved.

4.2. PBM reduces levels of pro-inflammatory cytokines in activated inflammatory cells

Part of the answer to the apparent contradiction highlighted above, was addressed in a subsequent paper [44]. We isolated primary bone marrow-derived dendritic cells (DCs) from the mouse femur and cultured them with GM-CSF. When these cells were activated with the classical toll-like receptor (TLR) agonists, LPS (TLR4) and CpG oligodeoxynucleotide (TLR9), they showed upregulation of cell-surface markers of activation and maturation such as MHC class II, CD86 and CD11c as measured by flow cytometry. Moreover IL12 was secreted by CpG-stimulated DCs. PBM (0.3 or 3 J/cm2 of 810 nm laser) reduced all the markers of activation and also the IL12 secretion. Figure 5.

Yamaura et al [45] tested PBM (810 nm, 5 or 25 J/cm2) on synoviocytes isolated from rheumatoid arthritis patients. They applied PBM before or after addition of tumor necrosis factor-α (TNF-α). mRNA and protein levels of TNF-α and interleukins (IL)-1beta, and IL-8 were reduced (especially by 25 J/cm2).

Hwang et al [46] incubated human annulus fibrosus cells with conditioned medium obtained from macrophages (THP-1 cells) containing proinflammatory cytokines IL1β, IL6, IL8 and TNF-α. They compared 405, 532 and 650 nm at doses up to 1.6 J/cm2. They found that all wavelengths reduced IL8 expression and 405 nm also reduced IL6.

The “Super-Lizer” is a Japanese device that emits linear polarized infrared light. Imaoka et al [47] tested it against a rat model of rheumatoid arthritis involving immunizing the rats with bovine type II collagen, after which they develop autoimmune inflammation in multiple joints. The found reductions in IL20 expression in histological sections taken from the PBM-treated joints and also in human rheumatoid fibroblast-like synoviocyte (MH7A) stimulated with IL1β.

Lim et al [48] studied human gingival fibroblasts (HGF) treated with lipopolysaccharides (LPS) isolated from Porphyromonas gingivalis. They used PBM mediated by a 635 nm LED and irradiated the cells + LPS directly or indirectly (transferring medium from PBM treated cells to other cells with LPS). Both direct and indirect protocols showed reductions in inflammatory markers (cyclooxygenase-2 (COX2), prostaglandin E2 (PGE2), granulocyte colony-stimulating factor (GCSF), regulated on activated normal T-cell expressed and secreted (RANTES), and CXCL11). In the indirect irradiation group, phosphorylation of C-Raf and Erk1/2 increased. In another study [49] the same group used a similar system (direct PBM on HGF + LPS) and showed that 635 nm PBM reduced IL6, IL8, p38 phosphorylation, and increased JNK phosphorylation. They explained the activation of JNK by the growth promoting effects of PBM. Sakurai et al reported [50] similar findings using HGF treated with Campylobacter rectus LPS and PBM (830 nm up to 6.3 J/cm2) to reduce levels of COX2 and PGE2. In another study [51] the same group showed a reduction in IL1β in the same system.

4.3. Effects of PBM on macrophage phenotype

Another very interesting property of PBM is its ability to change the phenotype of activated cells of the monocyte or macrophage lineage. These cells can display two very different phenotypes depending on which pathological situation the cells are faced with. The M1 phenotype (classically activated) applies to macrophages that are faced with a situation in which bacteria or other pathogens need to be killed, or alternatively tumor cells need to be destroyed. Inducible nitric oxide synthase is a hallmark of the M1 phenotype and nitric oxide secretion is often measured. On the other hand the M2 phenotype (alternatively activated) applies to macrophages that are involved in disposal of cellular or protein debris and stimulation of healing by angiogenesis. The M2 phenotype produces arginase, an enzyme that inhibits NO production and allows them to produce ornithine, a precursor of hydroxyproline and polyamines [52]. The markers of these two phenotypes of activated macrophage have some aspects in common, but also show many aspects that are very different [53]. It should be noted that this concept of M1 and M2 activation states, applies to other specialized macrophage type cells that are resident in different tissues, such as microglia in brain [54], alveolar macrophages in lung [55], Kuppfer cells in liver [56], etc.

Fernandes et al used J774 macrophage-like cells activated with interferon-γ and LPS to produce a MI phenotype and compared 660 nm and 780 nm laser. They found that both wavelengths reduced TNF-α, COX-2 and iNOS expression, with the 780 nm being somewhat better [57]. Silva et al used RAW264.7 macrophages to test two wavelengths (660 nm and 808 nm) at a range of fluences (11-214 J/cm2) [58]. They found increases in NO release with 660 nm at the higher fluences. von Leden et al carried out an interesting study looking at the effects of PBM on microglia and their interaction with cortical neurons [59]. They used both primary microglia isolated from mouse brains and the BV2 mouse microglial cell line and compared four fluences (0.2, 4, 10, and 30 J/cm2, at 808 nm. Fluences between 4 and 30 J/cm2 induced expression of M1 markers in microglia. Markers of the M2 phenotype, including CD206 and TIMP1, were observed at lower energy densities of 0.2–10 J/cm2. In addition, co-culture of PBM or control-treated microglia with primary neuronal cultures demonstrated a dose-dependent effect of PBM on microglial-induced neuronal growth and neurite extension. This suggests that the benefits of PBM on neuroinflammation may be more pronounced at lower overall doses. The same group went on to show that M1 activated macrophages receiving PBM (660 nm laser) showed significant decreases in CCL3, CXCL2 and TNFα mRNA expression 4 h after irradiation [60]. However, 24 h after irradiation, M1 macrophages showed increased expression of CXCL2 and TNFα genes. M1 activated macrophages irradiated with 780 nm showed a significant decrease in CCL3 gene expression 4h after irradiation. These data could explain the anti-inflammatory effects of LLLT in wound repair.

This section will cover some of the most important medical indications where PBM has been shown in laboratory studies to be effective (at least partly) by its pronounced anti-inflammatory effects. Figure 6 shows a graphical summary of the anti-inflammatory applications of PBM in experimental animal models.

5.1. Wound healing

Many papers have demonstrated the efficacy of PBM in stimulating wound healing. In animal models these studies have generally been on acute wounds [61], while in clinical trials they are often been concerned with chronic non-healing wounds such as diabetic ulcers [62]. Gupta et al [63] tested PBM using a superpulsed 904 nm laser on burn wounds in rats. They found faster healing, reduced inflammation (histology), decreased expression of TNF-α and NF-kB, and up-regulated expression of VEGF, FGFR-1, HSP-60, HSP-90, HIF-1α and matrix metalloproteinases-2 and 9 compared to controls. It is intriguing to speculate that the effects of PBM on wound healing (especially the use of for chronic non-healing wounds) could involve both pro-inflammatory effects and anti-inflammatory effects. This seemingly contradictory statement may be possible due to the recent discovery of resolvins and protectins, which are multifunctional lipid mediators derived from omega-3 polyunsaturated fatty acids [64]. If resolvins were produced as a result of the brief acute inflammation induced by application of PBM to chronic wounds, then it has been already shown that resolvins can hasten the healing of diabetic wounds in mice [65]. Resolvins have been shown to reduce tumor necrosis factor-α, interleukin-1β, and neutrophil platelet-endothelial cell adhesion molecule-1 in a mouse burn wound model [66].

5.2. Arthritis

In humans, arthritis is most often caused by a degenerative process occurring in osteoarthritis, or an autoimmune process occurring in rheumatoid arthritis. Both are characterized by pronounced inflammatory changes in the joint and even systemically. Different animal models are produced to mimic these diseases, but a common approach is to inject the sterile preparation of yeast cell walls known as zymosan into the knee joints of rats.

Castano et al [67] used this zymosan-induced arthritis model to study the effects of two different fluences of 810 nm laser (3 and 30 J/cm2) delivered at two different power densities (5 and 50 mW/cm2). PBM was delivered once a day for 5 days commencing after zymosan injection, and the swelling in the knee was measured daily. Prostagladin E2 (PGE2) was measured in the serum. They found that 3 out of the 4 sets of parameters were approximately equally effective in reducing swelling and PGE2, but the ineffective set of parameters was 3 J/cm2 delivered at 50 mW/cm2 which only took 1 min of illumination time. The conclusion was, that the illumination time was important in PBM, and if that time was too short, then the treatment could be ineffective.

Moriyama et al [68] used a transgenic mouse strain (FVB/N-Tg(iNOS-luc) that had been engineered to express luciferase under control of the inducible nitric oxide synthase promoter, to allow bioluminescence imaging of PBM of the zymosal-induced arthritis model in mice knees. They compared the same fluence of 635, 660, 690, and 905 nm (CW0 and 905 nm (short pulse). Animals younger than 15 weeks showed mostly reduction of iNOS expression, while older animals showed increased iNOS expression. Pulsed 905 nm also increased iNOS expression.

Pallotta et al [69] used a model where carageenan was injected into the rat knee and tested 810 nm laser at 1, 3, 6 or 10 J/cm2. Rats were sacrificed after 6 or 12 hours and the joint tissue removed. PBM was able to significantly inhibit the total number of leukocytes, as well as the myeloperoxidase activity. Vascular extravasation was significantly inhibited at the higher dose of energy of 10 J. Gene expression of both COX-1 and 2 were significantly enhanced by laser irradiation while PGE2 production was inhibited. These apparently contradictory results require more study to fully explain.

5.3. Muscles

One of the most robust applications of PBM, is its effects on muscles [70,71]. PBM can potentiate muscular performance especially when applied to the muscles 3 hours before exercise [72]. PBM can also make exercise-training regimens more effective. It is not therefore surprising that PBM can also help to heal muscle injuries, not to mention reducing muscle pain and soreness after excessive exercise. Many of the animal studies that have been done have looked at markers of inflammation and oxidative stress in muscle tissue removed from sacrificed animals. For instance, Silveira et al [73] caused a traumatic muscle injury by a single blunt-impact to the rat gastrocnemius muscle. PBM (850 nm, 3 or 5 J/cm2) was initiated 2, 12, and 24  h after muscle trauma, and repeated for five days. The locomotion and muscle function was improved by PBM. TBARS, protein carbonyls, superoxide dismutase, glutathione peroxidase, and catalase, were increased after muscle injury, these increases were prevented by PBM. PBM prevented increases in IL-6 and IL-10 and reversed the trauma-induced reduction in BDNF and VEGF.

5.4. Inflammatory pain

There have been many studies that have looked at the effects of PBM on pain in animal models. Some studies have looked at sensitivity to pain [74] using the von Frey filaments (a graded set of fibers of increasing stiffness and when the animal feels the pressure it withdraws its foot [75]).

Some studies have looked at animal models of neuropathic pain such as the “spared nerve injury” [76]. This involves ligating two out of three branches of the sciatic nerve in rats and causes long lasting (>6 months) mechanical allodynia [77]. Kobelia Ketz et al found improvements in pain scores with PBM (980  nm applied to affected hind paw 1 W, 20 s, 41 cm above skin, power density 43.25  mW/cm2, dose 20 J). They also found lower expression of the proinflammatory marker (Iba1) in microglia in the dorsal root ganglion, gracile nucleus, dorsal column and dorsal horn. The M1/M2 balance of the macrophage phenotype was switched from M1 to M2 by PBM, as judged by relative staining with anti-CD86 (M1) and anti-CD206 (M2).

Martins et al looked at the effect of PBM on a model of inflammatory pain [42]. This involved injecting complete Freund's adjuvant (CFA) into the mouse paw, and produces hyperalgesia and elevated cytokine levels (TNF-α, IL-1β, IL-10). They found that LEDT (950-nm, 80 mW/cm2, 1, 2 or 4 J/cm2) applied to the plantar aspect of the right hind limb, reduced pain, increased the levels of IL-10 prevented TBARS increase in both acute and chronic phases, reduced protein carbonyl levels and increased SOD and CAT activity in the acute phase only.

5.5. Lung inflammation

Aimbire and his laboratory in Brazil have carried out several studies on the use of PBM to reduce acute lung inflammation (ALI) in various animal models. In a mouse model of lung inflammation caused either by inhalation of lipolysaccharide or intranasal administration of TNFα they analyzed the bronchoalveolar lavage fluid (BALF). PBM (660 nm, 4.5 J/cm2) was administered to the skin over the right upper bronchus 15 min after ALI induction. PBM attenuated the neutrophil influx and lowered TNFα in BALF. In alveolar macrophages, PBM increased cAMP and reduced TNFα mRNA.

They also studied a different model of ALI caused by intestinal ischemia and reperfusion (I/R), that produces an analogue of acute respiratory distress syndrome (ARDS) [78]. Rats were subjected to superior mesenteric artery occlusion (45 min) and received PBM (660 nm, 7.5 J/cm2) carried out by irradiating the rats on the skin over the right upper bronchus for 15 and 30 min, and rats were euthanized 30 min, 2, or 4 h later. PBM reduced lung edema, myeloperoxisdase activity, TNF-α and iNOS, LLLT increased IL-10 in the lungs of animals subjected to I/R.

A third animal model was related to asthma [79]. Mice were sensitized to ovalbumin (OVA), and then challenged by a single 15-min exposure to aerosolized OVA. PBM was applied as above (660 nm, 30 mW, 5.4 J). Bronchial hyper-responsiveness (as measured by dose response curves to acetylcholine) was reduced by PBM as well as reductions in eosinophils and eotaxin. PBM also diminished expression of intracellular adhesion molecule and Th2 cytokines, as well as signal transducer and activator of transduction 6 (STAT6) levels in lungs from challenged mice. Recently Rigonato-Oliveira et al. presented a study that concluded that the reduced lung inflammation and the positive effects of PBM on the airways appear to be mediated by increased secretion of the anti-inflammatory cytokine IL-10, and reduction of mucus in the airway [80].

5.6. Traumatic brain injury

In recent years the use of PBM as a treatment for traumatic brain injury [81,82], and other brain disorders including stroke, neurodegenerative diseases and even psychiatric disorders has increased markedly [83]. It is thought that the actions of NIR light shone on the head and penetrating into the brain are multi-factorial, but one clear effect is the anti-inflammatory action of transcranial PBM. This was shown by a series of mouse experiments conducted by Khuman et al [84]. They used the controlled cortical impact model of TBI and delivered PBM (800  nm) was applied directly to the contused parenchyma or transcranially in mice beginning 60–80 min after CCI. Injured mice treated with 60 J/cm2 (500  mW/cm2 × 2  min) had improved latency to the hidden platform and probe trial performance in the Morris water maze. PBM in open craniotomy mice reduced the number of activated microglia in the brain at 48  h (21.8 ± 2.3 versus 39.2 ± 4.2 IbA-1 + cells/field).

5.7. Spinal cord injury

Spinal cord injury (SCI) is another promising area of central nervous system injury that could be benefited by PBM. Veronez et al [85] used a rat model of SCI involving a contusion produced by a mechanical impactor (between the ninth and tenth thoracic vertebrae), with a pressure of 150 kdyn. Three different doses of PBM (808-nm laser) were tested: 500 J/cm2, 750 J/cm2 and 1000 J/cm2 delivered daily for seven days. Functional preformance and tactile sensitivity were improved after PBM, at 1000 J/cm2. PBM at 750 and 1000 J/cm2 reduced the lesion volume and also reduced markers of inflammation (lower CD-68 protein expression).

5.8. Autoimmune diseases

Experimental autoimmune encephalomyelitis (EAE) is the most commonly studied animal model of multiple sclerosis (MS), a chronic autoimmune demyelinating disorder of the central nervous system. Immunomodulatory and immunosuppressive therapies currently approved for the treatment of MS slow disease progression, but do not prevent it. Lyons et al [86] studied a mouse model of EAE involving immunization with myelin oligodendrocyte glycoprotein (MOG35-55). They treated the female C57BL/6 mice with PBM (670 nm) for several days in different regimens. In addition to improved muscular function, they found down-regulation of inducible nitric oxide synthase (iNOS) gene expression in the spinal cords of mice as well as an up-regulation of the Bcl-2 anti-apoptosis gene, an increased Bcl-2:Bax ratio, and reduced apoptosis within the spinal cord of animals over the course of disease. 670 nm light therapy failed to ameliorate MOG-induced EAE in mice deficient in iNOS, confirming a role for remediation of nitrosative stress in the amelioration of MOG-induced EAE by 670 nm mediated photobiomodulation.

5.1. Wound healing

Many papers have demonstrated the efficacy of PBM in stimulating wound healing. In animal models these studies have generally been on acute wounds [61], while in clinical trials they are often been concerned with chronic non-healing wounds such as diabetic ulcers [62]. Gupta et al [63] tested PBM using a superpulsed 904 nm laser on burn wounds in rats. They found faster healing, reduced inflammation (histology), decreased expression of TNF-α and NF-kB, and up-regulated expression of VEGF, FGFR-1, HSP-60, HSP-90, HIF-1α and matrix metalloproteinases-2 and 9 compared to controls. It is intriguing to speculate that the effects of PBM on wound healing (especially the use of for chronic non-healing wounds) could involve both pro-inflammatory effects and anti-inflammatory effects. This seemingly contradictory statement may be possible due to the recent discovery of resolvins and protectins, which are multifunctional lipid mediators derived from omega-3 polyunsaturated fatty acids [64]. If resolvins were produced as a result of the brief acute inflammation induced by application of PBM to chronic wounds, then it has been already shown that resolvins can hasten the healing of diabetic wounds in mice [65]. Resolvins have been shown to reduce tumor necrosis factor-α, interleukin-1β, and neutrophil platelet-endothelial cell adhesion molecule-1 in a mouse burn wound model [66].

5.2. Arthritis

In humans, arthritis is most often caused by a degenerative process occurring in osteoarthritis, or an autoimmune process occurring in rheumatoid arthritis. Both are characterized by pronounced inflammatory changes in the joint and even systemically. Different animal models are produced to mimic these diseases, but a common approach is to inject the sterile preparation of yeast cell walls known as zymosan into the knee joints of rats.

Castano et al [67] used this zymosan-induced arthritis model to study the effects of two different fluences of 810 nm laser (3 and 30 J/cm2) delivered at two different power densities (5 and 50 mW/cm2). PBM was delivered once a day for 5 days commencing after zymosan injection, and the swelling in the knee was measured daily. Prostagladin E2 (PGE2) was measured in the serum. They found that 3 out of the 4 sets of parameters were approximately equally effective in reducing swelling and PGE2, but the ineffective set of parameters was 3 J/cm2 delivered at 50 mW/cm2 which only took 1 min of illumination time. The conclusion was, that the illumination time was important in PBM, and if that time was too short, then the treatment could be ineffective.

Moriyama et al [68] used a transgenic mouse strain (FVB/N-Tg(iNOS-luc) that had been engineered to express luciferase under control of the inducible nitric oxide synthase promoter, to allow bioluminescence imaging of PBM of the zymosal-induced arthritis model in mice knees. They compared the same fluence of 635, 660, 690, and 905 nm (CW0 and 905 nm (short pulse). Animals younger than 15 weeks showed mostly reduction of iNOS expression, while older animals showed increased iNOS expression. Pulsed 905 nm also increased iNOS expression.

Pallotta et al [69] used a model where carageenan was injected into the rat knee and tested 810 nm laser at 1, 3, 6 or 10 J/cm2. Rats were sacrificed after 6 or 12 hours and the joint tissue removed. PBM was able to significantly inhibit the total number of leukocytes, as well as the myeloperoxidase activity. Vascular extravasation was significantly inhibited at the higher dose of energy of 10 J. Gene expression of both COX-1 and 2 were significantly enhanced by laser irradiation while PGE2 production was inhibited. These apparently contradictory results require more study to fully explain.

5.3. Muscles

One of the most robust applications of PBM, is its effects on muscles [70,71]. PBM can potentiate muscular performance especially when applied to the muscles 3 hours before exercise [72]. PBM can also make exercise-training regimens more effective. It is not therefore surprising that PBM can also help to heal muscle injuries, not to mention reducing muscle pain and soreness after excessive exercise. Many of the animal studies that have been done have looked at markers of inflammation and oxidative stress in muscle tissue removed from sacrificed animals. For instance, Silveira et al [73] caused a traumatic muscle injury by a single blunt-impact to the rat gastrocnemius muscle. PBM (850 nm, 3 or 5 J/cm2) was initiated 2, 12, and 24  h after muscle trauma, and repeated for five days. The locomotion and muscle function was improved by PBM. TBARS, protein carbonyls, superoxide dismutase, glutathione peroxidase, and catalase, were increased after muscle injury, these increases were prevented by PBM. PBM prevented increases in IL-6 and IL-10 and reversed the trauma-induced reduction in BDNF and VEGF.

5.4. Inflammatory pain

There have been many studies that have looked at the effects of PBM on pain in animal models. Some studies have looked at sensitivity to pain [74] using the von Frey filaments (a graded set of fibers of increasing stiffness and when the animal feels the pressure it withdraws its foot [75]).

Some studies have looked at animal models of neuropathic pain such as the “spared nerve injury” [76]. This involves ligating two out of three branches of the sciatic nerve in rats and causes long lasting (>6 months) mechanical allodynia [77]. Kobelia Ketz et al found improvements in pain scores with PBM (980  nm applied to affected hind paw 1 W, 20 s, 41 cm above skin, power density 43.25  mW/cm2, dose 20 J). They also found lower expression of the proinflammatory marker (Iba1) in microglia in the dorsal root ganglion, gracile nucleus, dorsal column and dorsal horn. The M1/M2 balance of the macrophage phenotype was switched from M1 to M2 by PBM, as judged by relative staining with anti-CD86 (M1) and anti-CD206 (M2).

Martins et al looked at the effect of PBM on a model of inflammatory pain [42]. This involved injecting complete Freund's adjuvant (CFA) into the mouse paw, and produces hyperalgesia and elevated cytokine levels (TNF-α, IL-1β, IL-10). They found that LEDT (950-nm, 80 mW/cm2, 1, 2 or 4 J/cm2) applied to the plantar aspect of the right hind limb, reduced pain, increased the levels of IL-10 prevented TBARS increase in both acute and chronic phases, reduced protein carbonyl levels and increased SOD and CAT activity in the acute phase only.

5.5. Lung inflammation

Aimbire and his laboratory in Brazil have carried out several studies on the use of PBM to reduce acute lung inflammation (ALI) in various animal models. In a mouse model of lung inflammation caused either by inhalation of lipolysaccharide or intranasal administration of TNFα they analyzed the bronchoalveolar lavage fluid (BALF). PBM (660 nm, 4.5 J/cm2) was administered to the skin over the right upper bronchus 15 min after ALI induction. PBM attenuated the neutrophil influx and lowered TNFα in BALF. In alveolar macrophages, PBM increased cAMP and reduced TNFα mRNA.

They also studied a different model of ALI caused by intestinal ischemia and reperfusion (I/R), that produces an analogue of acute respiratory distress syndrome (ARDS) [78]. Rats were subjected to superior mesenteric artery occlusion (45 min) and received PBM (660 nm, 7.5 J/cm2) carried out by irradiating the rats on the skin over the right upper bronchus for 15 and 30 min, and rats were euthanized 30 min, 2, or 4 h later. PBM reduced lung edema, myeloperoxisdase activity, TNF-α and iNOS, LLLT increased IL-10 in the lungs of animals subjected to I/R.

A third animal model was related to asthma [79]. Mice were sensitized to ovalbumin (OVA), and then challenged by a single 15-min exposure to aerosolized OVA. PBM was applied as above (660 nm, 30 mW, 5.4 J). Bronchial hyper-responsiveness (as measured by dose response curves to acetylcholine) was reduced by PBM as well as reductions in eosinophils and eotaxin. PBM also diminished expression of intracellular adhesion molecule and Th2 cytokines, as well as signal transducer and activator of transduction 6 (STAT6) levels in lungs from challenged mice. Recently Rigonato-Oliveira et al. presented a study that concluded that the reduced lung inflammation and the positive effects of PBM on the airways appear to be mediated by increased secretion of the anti-inflammatory cytokine IL-10, and reduction of mucus in the airway [80].

5.6. Traumatic brain injury

In recent years the use of PBM as a treatment for traumatic brain injury [81,82], and other brain disorders including stroke, neurodegenerative diseases and even psychiatric disorders has increased markedly [83]. It is thought that the actions of NIR light shone on the head and penetrating into the brain are multi-factorial, but one clear effect is the anti-inflammatory action of transcranial PBM. This was shown by a series of mouse experiments conducted by Khuman et al [84]. They used the controlled cortical impact model of TBI and delivered PBM (800  nm) was applied directly to the contused parenchyma or transcranially in mice beginning 60–80 min after CCI. Injured mice treated with 60 J/cm2 (500  mW/cm2 × 2  min) had improved latency to the hidden platform and probe trial performance in the Morris water maze. PBM in open craniotomy mice reduced the number of activated microglia in the brain at 48  h (21.8 ± 2.3 versus 39.2 ± 4.2 IbA-1 + cells/field).

5.7. Spinal cord injury

Spinal cord injury (SCI) is another promising area of central nervous system injury that could be benefited by PBM. Veronez et al [85] used a rat model of SCI involving a contusion produced by a mechanical impactor (between the ninth and tenth thoracic vertebrae), with a pressure of 150 kdyn. Three different doses of PBM (808-nm laser) were tested: 500 J/cm2, 750 J/cm2 and 1000 J/cm2 delivered daily for seven days. Functional preformance and tactile sensitivity were improved after PBM, at 1000 J/cm2. PBM at 750 and 1000 J/cm2 reduced the lesion volume and also reduced markers of inflammation (lower CD-68 protein expression).

5.8. Autoimmune diseases

Experimental autoimmune encephalomyelitis (EAE) is the most commonly studied animal model of multiple sclerosis (MS), a chronic autoimmune demyelinating disorder of the central nervous system. Immunomodulatory and immunosuppressive therapies currently approved for the treatment of MS slow disease progression, but do not prevent it. Lyons et al [86] studied a mouse model of EAE involving immunization with myelin oligodendrocyte glycoprotein (MOG35-55). They treated the female C57BL/6 mice with PBM (670 nm) for several days in different regimens. In addition to improved muscular function, they found down-regulation of inducible nitric oxide synthase (iNOS) gene expression in the spinal cords of mice as well as an up-regulation of the Bcl-2 anti-apoptosis gene, an increased Bcl-2:Bax ratio, and reduced apoptosis within the spinal cord of animals over the course of disease. 670 nm light therapy failed to ameliorate MOG-induced EAE in mice deficient in iNOS, confirming a role for remediation of nitrosative stress in the amelioration of MOG-induced EAE by 670 nm mediated photobiomodulation.

5.1. Wound healing

Many papers have demonstrated the efficacy of PBM in stimulating wound healing. In animal models these studies have generally been on acute wounds [61], while in clinical trials they are often been concerned with chronic non-healing wounds such as diabetic ulcers [62]. Gupta et al [63] tested PBM using a superpulsed 904 nm laser on burn wounds in rats. They found faster healing, reduced inflammation (histology), decreased expression of TNF-α and NF-kB, and up-regulated expression of VEGF, FGFR-1, HSP-60, HSP-90, HIF-1α and matrix metalloproteinases-2 and 9 compared to controls. It is intriguing to speculate that the effects of PBM on wound healing (especially the use of for chronic non-healing wounds) could involve both pro-inflammatory effects and anti-inflammatory effects. This seemingly contradictory statement may be possible due to the recent discovery of resolvins and protectins, which are multifunctional lipid mediators derived from omega-3 polyunsaturated fatty acids [64]. If resolvins were produced as a result of the brief acute inflammation induced by application of PBM to chronic wounds, then it has been already shown that resolvins can hasten the healing of diabetic wounds in mice [65]. Resolvins have been shown to reduce tumor necrosis factor-α, interleukin-1β, and neutrophil platelet-endothelial cell adhesion molecule-1 in a mouse burn wound model [66].

5.2. Arthritis

In humans, arthritis is most often caused by a degenerative process occurring in osteoarthritis, or an autoimmune process occurring in rheumatoid arthritis. Both are characterized by pronounced inflammatory changes in the joint and even systemically. Different animal models are produced to mimic these diseases, but a common approach is to inject the sterile preparation of yeast cell walls known as zymosan into the knee joints of rats.

Castano et al [67] used this zymosan-induced arthritis model to study the effects of two different fluences of 810 nm laser (3 and 30 J/cm2) delivered at two different power densities (5 and 50 mW/cm2). PBM was delivered once a day for 5 days commencing after zymosan injection, and the swelling in the knee was measured daily. Prostagladin E2 (PGE2) was measured in the serum. They found that 3 out of the 4 sets of parameters were approximately equally effective in reducing swelling and PGE2, but the ineffective set of parameters was 3 J/cm2 delivered at 50 mW/cm2 which only took 1 min of illumination time. The conclusion was, that the illumination time was important in PBM, and if that time was too short, then the treatment could be ineffective.

Moriyama et al [68] used a transgenic mouse strain (FVB/N-Tg(iNOS-luc) that had been engineered to express luciferase under control of the inducible nitric oxide synthase promoter, to allow bioluminescence imaging of PBM of the zymosal-induced arthritis model in mice knees. They compared the same fluence of 635, 660, 690, and 905 nm (CW0 and 905 nm (short pulse). Animals younger than 15 weeks showed mostly reduction of iNOS expression, while older animals showed increased iNOS expression. Pulsed 905 nm also increased iNOS expression.

Pallotta et al [69] used a model where carageenan was injected into the rat knee and tested 810 nm laser at 1, 3, 6 or 10 J/cm2. Rats were sacrificed after 6 or 12 hours and the joint tissue removed. PBM was able to significantly inhibit the total number of leukocytes, as well as the myeloperoxidase activity. Vascular extravasation was significantly inhibited at the higher dose of energy of 10 J. Gene expression of both COX-1 and 2 were significantly enhanced by laser irradiation while PGE2 production was inhibited. These apparently contradictory results require more study to fully explain.

5.3. Muscles

One of the most robust applications of PBM, is its effects on muscles [70,71]. PBM can potentiate muscular performance especially when applied to the muscles 3 hours before exercise [72]. PBM can also make exercise-training regimens more effective. It is not therefore surprising that PBM can also help to heal muscle injuries, not to mention reducing muscle pain and soreness after excessive exercise. Many of the animal studies that have been done have looked at markers of inflammation and oxidative stress in muscle tissue removed from sacrificed animals. For instance, Silveira et al [73] caused a traumatic muscle injury by a single blunt-impact to the rat gastrocnemius muscle. PBM (850 nm, 3 or 5 J/cm2) was initiated 2, 12, and 24  h after muscle trauma, and repeated for five days. The locomotion and muscle function was improved by PBM. TBARS, protein carbonyls, superoxide dismutase, glutathione peroxidase, and catalase, were increased after muscle injury, these increases were prevented by PBM. PBM prevented increases in IL-6 and IL-10 and reversed the trauma-induced reduction in BDNF and VEGF.

5.4. Inflammatory pain

There have been many studies that have looked at the effects of PBM on pain in animal models. Some studies have looked at sensitivity to pain [74] using the von Frey filaments (a graded set of fibers of increasing stiffness and when the animal feels the pressure it withdraws its foot [75]).

Some studies have looked at animal models of neuropathic pain such as the “spared nerve injury” [76]. This involves ligating two out of three branches of the sciatic nerve in rats and causes long lasting (>6 months) mechanical allodynia [77]. Kobelia Ketz et al found improvements in pain scores with PBM (980  nm applied to affected hind paw 1 W, 20 s, 41 cm above skin, power density 43.25  mW/cm2, dose 20 J). They also found lower expression of the proinflammatory marker (Iba1) in microglia in the dorsal root ganglion, gracile nucleus, dorsal column and dorsal horn. The M1/M2 balance of the macrophage phenotype was switched from M1 to M2 by PBM, as judged by relative staining with anti-CD86 (M1) and anti-CD206 (M2).

Martins et al looked at the effect of PBM on a model of inflammatory pain [42]. This involved injecting complete Freund's adjuvant (CFA) into the mouse paw, and produces hyperalgesia and elevated cytokine levels (TNF-α, IL-1β, IL-10). They found that LEDT (950-nm, 80 mW/cm2, 1, 2 or 4 J/cm2) applied to the plantar aspect of the right hind limb, reduced pain, increased the levels of IL-10 prevented TBARS increase in both acute and chronic phases, reduced protein carbonyl levels and increased SOD and CAT activity in the acute phase only.

5.5. Lung inflammation

Aimbire and his laboratory in Brazil have carried out several studies on the use of PBM to reduce acute lung inflammation (ALI) in various animal models. In a mouse model of lung inflammation caused either by inhalation of lipolysaccharide or intranasal administration of TNFα they analyzed the bronchoalveolar lavage fluid (BALF). PBM (660 nm, 4.5 J/cm2) was administered to the skin over the right upper bronchus 15 min after ALI induction. PBM attenuated the neutrophil influx and lowered TNFα in BALF. In alveolar macrophages, PBM increased cAMP and reduced TNFα mRNA.

They also studied a different model of ALI caused by intestinal ischemia and reperfusion (I/R), that produces an analogue of acute respiratory distress syndrome (ARDS) [78]. Rats were subjected to superior mesenteric artery occlusion (45 min) and received PBM (660 nm, 7.5 J/cm2) carried out by irradiating the rats on the skin over the right upper bronchus for 15 and 30 min, and rats were euthanized 30 min, 2, or 4 h later. PBM reduced lung edema, myeloperoxisdase activity, TNF-α and iNOS, LLLT increased IL-10 in the lungs of animals subjected to I/R.

A third animal model was related to asthma [79]. Mice were sensitized to ovalbumin (OVA), and then challenged by a single 15-min exposure to aerosolized OVA. PBM was applied as above (660 nm, 30 mW, 5.4 J). Bronchial hyper-responsiveness (as measured by dose response curves to acetylcholine) was reduced by PBM as well as reductions in eosinophils and eotaxin. PBM also diminished expression of intracellular adhesion molecule and Th2 cytokines, as well as signal transducer and activator of transduction 6 (STAT6) levels in lungs from challenged mice. Recently Rigonato-Oliveira et al. presented a study that concluded that the reduced lung inflammation and the positive effects of PBM on the airways appear to be mediated by increased secretion of the anti-inflammatory cytokine IL-10, and reduction of mucus in the airway [80].

5.6. Traumatic brain injury

In recent years the use of PBM as a treatment for traumatic brain injury [81,82], and other brain disorders including stroke, neurodegenerative diseases and even psychiatric disorders has increased markedly [83]. It is thought that the actions of NIR light shone on the head and penetrating into the brain are multi-factorial, but one clear effect is the anti-inflammatory action of transcranial PBM. This was shown by a series of mouse experiments conducted by Khuman et al [84]. They used the controlled cortical impact model of TBI and delivered PBM (800  nm) was applied directly to the contused parenchyma or transcranially in mice beginning 60–80 min after CCI. Injured mice treated with 60 J/cm2 (500  mW/cm2 × 2  min) had improved latency to the hidden platform and probe trial performance in the Morris water maze. PBM in open craniotomy mice reduced the number of activated microglia in the brain at 48  h (21.8 ± 2.3 versus 39.2 ± 4.2 IbA-1 + cells/field).

5.7. Spinal cord injury

Spinal cord injury (SCI) is another promising area of central nervous system injury that could be benefited by PBM. Veronez et al [85] used a rat model of SCI involving a contusion produced by a mechanical impactor (between the ninth and tenth thoracic vertebrae), with a pressure of 150 kdyn. Three different doses of PBM (808-nm laser) were tested: 500 J/cm2, 750 J/cm2 and 1000 J/cm2 delivered daily for seven days. Functional preformance and tactile sensitivity were improved after PBM, at 1000 J/cm2. PBM at 750 and 1000 J/cm2 reduced the lesion volume and also reduced markers of inflammation (lower CD-68 protein expression).

5.8. Autoimmune diseases

Experimental autoimmune encephalomyelitis (EAE) is the most commonly studied animal model of multiple sclerosis (MS), a chronic autoimmune demyelinating disorder of the central nervous system. Immunomodulatory and immunosuppressive therapies currently approved for the treatment of MS slow disease progression, but do not prevent it. Lyons et al [86] studied a mouse model of EAE involving immunization with myelin oligodendrocyte glycoprotein (MOG35-55). They treated the female C57BL/6 mice with PBM (670 nm) for several days in different regimens. In addition to improved muscular function, they found down-regulation of inducible nitric oxide synthase (iNOS) gene expression in the spinal cords of mice as well as an up-regulation of the Bcl-2 anti-apoptosis gene, an increased Bcl-2:Bax ratio, and reduced apoptosis within the spinal cord of animals over the course of disease. 670 nm light therapy failed to ameliorate MOG-induced EAE in mice deficient in iNOS, confirming a role for remediation of nitrosative stress in the amelioration of MOG-induced EAE by 670 nm mediated photobiomodulation.

5.9. Abdominal fat

Yoshimura et al [87] looked at a mouse model of obesity and type 2 diabetes [87]. Four weeks old male adult C57BL/6 mice were fed a hypercaloric high-fat diet (40% calories derived from fat) for eight weeks to induce obesity and hyperglycemia. Over a period of four weeks mice were exposed to six irradiation sessions using an 843 nm LED (5.7 J cm−2, 19 mW cm−2). Non-irradiated control mice had areas of inflammation in their abdominal fat almost five times greater than the PBM group. The PBM group had significantly lower blood glucose levels 24 hours after the last session.

Amongst the many hundreds of reports of clinical applications of PBMT, we will highlight a few here, which seem to be especially relevant to inflammation, and inflammatory disorders.

6.1. Achilles tendinopathy

Bjordal et al in Norway carried out a randomized, placebo controlled trial of PBM (904 nm, 5.4 J per point, 20 mW/cm2) for activated Achilles tendinitis [88]. In addition to clinical assessment, they used microdialysis measurement of peritendinous prostaglandin E2 concentrations. Doppler ultrasonography measurements at baseline showed minor inflammation shown by increased intratendinous blood flow, and a measurable resistive index. PGE2 concentrations were significantly reduced with PBM vs placebo. The pressure pain threshold also increased significantly.

6.2. Thyroiditis

Chavantes and Chammas in Brazil have studied PBM for chronic autoimmune thyroiditis. An initial pilot trial [89] used 10 applications of PBM (830 nm, 50 mW, 38–108 J/cm2), twice a week, using either the punctual technique (8 patients) or the sweep technique (7 patients). Patients required a lower dosage of levothyroxine, and showed an increased echogenicity by ultrasound. The next study [90] was a randomized, placebo-controlled trial of 43 patients with a 9-month follow-up. In addition to improved thyroid function they found reduced autoimmunity evidenced by lower thyroid peroxidase antibodies (TPOAb), and thyroglobulin antibodies (TgAb). A third study [91] used color Doppler ultrasound to show improved normal vascualrization in the thyroid parenchyma. Finally [92] they showed a statistically significant increase in serum TGF-β1 levels 30 days post-intervention in the PBM group, thus confirming the anti-inflammatory effect. Recently a long-term follow up study of these thyroiditis patients (6 years later) was presented showing that PBM was safe in the long term and demonstrated lasting benefits [93].

6.3. Muscles

PBM for muscles aims to benefit athletic performance and training, to reduce delayed onset muscle soreness (DOMS), as well as to ameliorate signs of muscle damage (creatine kinase) after intense or prolonged exercise. Moreover PBM can also be used to treat frank muscle damage caused by muscle strains or trauma. The International Olympic Committee and the World Anti-Doping Agency cannot ban light therapy for athletes considering (1) the intensity is similar to sunlight, and (2) there is no forensic test for light exposure. There have been several clinical trials carried out in Brazil in athletes such as elite runners [94], volleyball players [95] and rugby players [96]. Ferraresi et al conducted a case-controlled study in a pair of identical twins [97]. They used a flexible LED array (850 nm, 75 J, 15 sec) applied to both quadriceps femoris muscles (real to one twin and sham to the other) immediately after each strength training session (3 times/wk for 12 weeks) consisting of leg press and leg extension exercises with load of 80% and 50% of the 1-repetition maximum test, respectively. PBM increased the maximal load in exercise and reduced fatigue, creatine kinase, and visual analog scale (DOMS) compared to sham. Muscle biopsies were taken before and after the training program and showed that PBM decreased inflammatory markers such as interleukin 1β and muscle atrophy (myostatin). Protein synthesis (mammalian target of rapamycin) and oxidative stress defense (SOD2, mitochondrial superoxide dismutase) were up-regulated.

6.4. Psoriasis

Psoriasis is a chronic autoimmune skin disease. Psoriasis is characterized by the abnormally excessive and rapid growth of keratinocytes (instead of being replaced every 28–30 days as in normal skin, in psoriatic skin they are replaced every 3–5 days). This hyperproliferation is caused by an inflammatory cascade in the dermis involving dendritic cells, macrophages, and T cells secreting TNF-α, IL-1β, IL-6, IL-17, IL-22, and IL-36γ [98]. PBM has been used for psoriasis because of its anti-inflammatory effects, which is a different approach from UV phototherapy which tends to kill circulating T-cells. Ablon [99] tested PBM using LEDs (830 nm, 60 J/cm2 and 633 nm, 126 J/cm2) in two 20-min sessions over 4 or 5 weeks, with 48 h between sessions in 9 patients with chronic treatment-resistant psoriasis. Clearance rates at the end of the follow-up period ranged from 60% to 100%. Satisfaction was universally very high.

Choi et al [100] tested PBM in case report of a patient with another inflammatory skin disease called acrodermatitis continua, who also had a 10-yr history of plaque psoriasis on her knees and elbows. As she was pregnant and not suited for pharmacological therapy, she received treatment with PBM (broad-band polarized light, 480–3,400 nm, 10 J/cm2). In two weeks (after only 4 treatments), the clinical resolution was impressive and no pustules were found. Topical methylprednisolone aceponate steroid cream was switched to a moisturizer, and she was treated twice or once a week with PBM until a healthy baby was delivered.

6.5. Arthritis

As can be seen from the animal studies section, arthritis is one of the most important clinical indications for PBM [101,102]. The two most common forms of arthritis are osteoarthritis (degenerative joint disease that mostly affects the fingers, knees, and hips) and rheumatoid arthritis (autoimmune joint inflammation that often affects the hands and feet). Osteoarthritis (OA) affects more than 3.8% of the population while rheumatoid arthritis (RA) affects about 0.24%. Both types have been successfully treated with PBM. Cochrane systematic reviews found for good evidence for its effectiveness in RA [103], and some evidence in the case of OA [104]. Most clinical studies have used pain scales and range of movement scores to test the effectiveness, rather than measures of inflammation which are difficult to carry out in human subjects.

Barabas and coworkers [105] made an attempt by testing PBM on ex vivo samples of synovial tissue surgically removed from patients receiving knee joint replacement. Synovial membrane samples received exposure to PBM (810 nm, 448 mW, 25 J/cm2, 1 cm2 area). PBM caused an increase in mitochondrial heat shock protein 1 60 kD, and decreases in calpain small subunit 1, tubulin alpha-1C, beta 2,vimentin variant 3, annexin A1, annexin A5, cofilin 1,transgelin, and collagen type VI alpha 2 chain precursor all significantly decreased compared to the control

6.6. Alopecia areata

Alopecia areata (AA) is one of the three common types of hair loss, the other two being androgenetic alopecia (AGA, male pattern baldness) and chemotherapy induced alopecia. AA is a common autoimmune disease resulting from damage caused to the hair follicles (HFs) by T cells. Evidence of autoantibodies to anagen stage HF structures is found in affected humans and experimental mouse models. Biopsy specimens from affected individuals demonstrate a characteristic peri- and intrafollicular inflammatory infiltrate around anagen-stage HFs consisting of activated CD4 and CD8 T lymphocytes [106]. PBM is an excellent treatment for hair loss in general and AGA in particular [107,108]. Yamazaki et al [109] reported the use of the “Super-Lizer” delivering linear-polarized light between 600–1600 nm at a power of 1.26 W to the areas of hair loss on the scalp (4-s pulses delivered at 1-s intervals for 3 min every 1 or 2 weeks until hair growth was observed). Regrowth of vellus hairs was achieved on more than 50% ofthe involved areas in all 15 cases. The frequency of irradiation until regrowth ranged from one to 14 times and the duration of SL treatment was 2 weeks to 5 months.

7. Conclusion and Future Studies

The clinical applications of PBM have been increasing apace in recent years. The recent adoption of inexpensive large area LED arrays, that have replaced costly, small area laser beams with a risk of eye damage, has accelerated this increase in popularity. Advances in understanding of PBM mechanisms of action at a molecular and cellular level, have provided a scientific rationale for its use for multiple diseases. Many patients have become disillusioned with traditional pharmaceutical approaches to a range of chronic conditions, with their accompanying distressing side-effects and have turned to complementary and alternative medicine for more natural remedies. PBM has an almost complete lack of reported adverse effects, provided the parameters are understood at least at a basic level. The remarkable range of medical benefits provided by PBM, has led some to suggest that it may be “too good to be true”. However one of the most general benefits of PBM that has recently emerged, is its pronounced anti-inflammatory effects. While the exact cellular signaling pathways responsible for this anti-inflammatory action are not yet completely understood, it is becoming clear that both local and systemic mechanisms are operating. The local reduction of edema, and reductions in markers of oxidative stress and pro-inflammatory cytokines are well established. However there also appears to be a systemic effect whereby light delivered to the body, can positively benefit distant tissues and organs.

There is a lot of scope for further work on PBM and inflammation. The intriguing benefits of PBM on some autoimmune diseases, suggests that this area may present a fertile area for researchers. There may be some overlap between the ability of PBM to activate and mobilize stem cells and progenitor cells, and its anti-inflammatory action, considering that one of the main benefits of exogenous stem cell therapy has been found to be its anti-inflammatory effect. The versatile benefits of PBM on the brain and the central nervous system, encourages further study of its ability to reduce neuroinflammation. Chronic diseases of the modern age involving systemic inflammation such as type II diabetes, obesity, Alzheimer's disease, cardiovascular disease and endothelial dysfunction are again worth investigating in the context of PBM.


Original Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5523874/

Lasers, stem cells, and COPD

Feng Lin†, Steven F Josephs†, Doru T Alexandrescu†, Famela Ramos, Vladimir Bogin, Vincent Gammill, Constantin A Dasanu, Rosalia De Necochea-Campion, Amit N Patel, Ewa Carrier and David R Koos - 2010 (Publication)
This well annotated paper looks at the biphasic response to try to find the appropriate dosage for several applications including COPD.
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Lasers, stem cells, and COPD

·         Feng Lin,

·         Steven F Josephs,

·         Doru T Alexandrescu,

·         Famela Ramos,

·         Vladimir Bogin,

·         Vincent Gammill,

·         Constantin A Dasanu,

·         Rosalia De Necochea-Campion,

·         Amit N Patel,

·         Ewa Carrier and

·         David R KoosEmail author

Contributed equally

Journal of Translational Medicine20108:16

https://doi.org/10.1186/1479-5876-8-16

Received: 7 January 2010

Accepted: 16 February 2010

Published: 16 February 2010

Abstract

The medical use of low level laser (LLL) irradiation has been occurring for decades, primarily in the area of tissue healing and inflammatory conditions. Despite little mechanistic knowledge, the concept of a non-invasive, non-thermal intervention that has the potential to modulate regenerative processes is worthy of attention when searching for novel methods of augmenting stem cell-based therapies. Here we discuss the use of LLL irradiation as a "photoceutical" for enhancing production of stem cell growth/chemoattractant factors, stimulation of angiogenesis, and directly augmenting proliferation of stem cells. The combination of LLL together with allogeneic and autologous stem cells, as well as post-mobilization directing of stem cells will be discussed.

Introduction (Personal Perspective)

We came upon the field of low level laser (LLL) therapy by accident. One of our advisors read a press release about a company using this novel technology of specific light wavelengths to treat stroke. Given the possible role of stem cells in post-stroke regeneration, we decided to cautiously investigate. As a background, it should be said that our scientific team has been focusing on the area of cord blood banking and manufacturing of disposables for processing of adipose stem cells for the past 3 years. Our board has been interested in strategically refocusing the company from services-oriented into a more research-focused model. An unbiased exploration into the various degenerative conditions that may be addressed by our existing know-how led us to explore the condition of chronic obstructive pulmonary disease (COPD), an umbrella term covering chronic bronchitis and emphysema, which is the 4th largest cause of death in the United States. As a means of increasing our probability of success in treatment of this condition, the decision was made to develop an adjuvant therapy that would augment stem cell activity. The field of LLL therapy attracted us because it appeared to be relatively unexplored scientific territory for which large amounts of clinical experience exist. Unfortunately, it was difficult to obtain the cohesive "state-of-the-art" description of the molecular/cellular mechanisms of this therapy in reviews that we have searched. Therefore we sought in this mini-review to discuss what we believe to be relevant to investigators attracted by the concept of "regenerative photoceuticals". Before presenting our synthesis of the field, we will begin by describing our rationale for approaching COPD with the autologous stem cell based approaches we are developing.

COPD as an Indication for Stem Cell Therapy

COPD possesses several features making it ideal for stem cell based interventions: a) the quality of life and lack of progress demands the ethical exploration of novel approaches. For example, bone marrow stem cells have been used in over a thousand cardiac patients with some indication of efficacy [12]. Adipose-based stem cell therapies have been successfully used in thousands of race-horses and companion animals without adverse effects [3], as well as numerous clinical trials are ongoing and published human data reports no adverse effects (reviewed in ref [4]). Unfortunately, evaluation of stem cell therapy in COPD has lagged behind other areas of regenerative investigation; b) the underlying cause of COPD appears to be inflammatory and/or immunologically mediated. The destruction of alveolar tissue is associated with T cell reactivity [56], pathological pulmonary macrophage activation [7], and auto-antibody production [8]. Mesenchymal stem cells have been demonstrated to potently suppress autoreactive T cells [910], inhibit macrophage activation [11], and autoantibody responses [12]. Additionally, mesenchymal stem cells can be purified in high concentrations from adipose stromal vascular tissue together with high concentrations of T regulatory cells [4], which in animal models are approximately 100 more potent than peripheral T cells at secreting cytokines therapeutic for COPD such as IL-10 [1314]. Additionally, use of adipose derived cells has yielded promising clinical results in autoimmune conditions such as multiple sclerosis [4]; and c) Pulmonary stem cells capable of regenerating damaged parenchymal tissue have been reported [15]. Administration of mesenchymal stem cells into neonatal oxygen-damaged lungs, which results in COPD-like alveoli dysplasia, has been demonstrated to yield improvements in two recent publications [1617].

Based on the above rationale for stem cell-based COPD treatments, we began our exploration into this area by performing several preliminary experiments and filing patents covering combination uses of stem cells with various pharmacologically available antiinflammatories, as well as methods of immune modulation. These have served as the basis for two of our pipeline candidates, ENT-111, and ENT-894. As a commercially-oriented organization, we needed to develop a therapeutic candidate that not only has a great potential for efficacy, but also can be easily implemented as part of the standard of care. Our search led us to the area of low level laser (LLL) therapy. From our initial perception as neophytes to this field, the area of LLL therapy has been somewhat of a medical mystery. A pubmed search for "low level laser therapy" yields more than 1700 results, yet before stumbling across this concept, none of us, or our advisors, have ever heard of this area of medicine.

On face value, this field appeared to be somewhat of a panacea: clinical trials claiming efficacy for conditions ranging from alcoholism [18], to sinusitis [19], to ischemic heart disease [20]. Further confusing was that many of the studies used different types of LLL-generating devices, with different parameters, in different model systems, making comparison of data almost impossible. Despite this initial impression, the possibility that a simple, non-invasive methodology could exist that augments regenerative potential in a tissue-focused manner became very enticing to us. Specific uses envisioned, for which intellectual property was filed included using light to concentrate stem cells to an area of need, to modulate effects of stem cells once they are in that specific area, or even to use light together with other agents to modulate endogenous stem cells.

The purpose of the current manuscript is to overview some of the previous work performed in this area that was of great interest to our ongoing work in regenerative medicine. We believe that greater integration of the area of LLL with current advancements in molecular and cellular biology will accelerate medical progress. Unfortunately, in our impression to date, this has been a very slow process.

What is Low Level Laser Irradiation?

Lasers (Light amplification by stimulated emission of radiation) are devices that typically generate electromagnetic radiation which is relatively uniform in wavelength, phase, and polarization, originally described by Theodore Maiman in 1960 in the form of a ruby laser [21]. These properties have allowed for numerous medical applications including uses in surgery, activation of photodynamic agents, and various ablative therapies in cosmetics that are based on heat/tissue destruction generated by the laser beam [222324]. These applications of lasers are considered "high energy" because of their intensity, which ranges from about 10-100 Watts. The subject of the current paper will be another type of laser approach called low level lasers (LLL) that elicits effects through non-thermal means. This area of investigation started with the work of Mester et al who in 1967 reported non-thermal effects of lasers on mouse hair growth [25]. In a subsequent study [26], the same group reported acceleration of wound healing and improvement in regenerative ability of muscle fibers post wounding using a 1 J/cm2 ruby laser. Since those early days, numerous in vitro and in vivo studies have been reported demonstrating a wide variety of therapeutic effects involving LLL, a selected sample of which will be discussed below. In order to narrow our focus of discussion, it is important to first begin by establishing the current definition of LLL therapy. According to Posten et al [27], there are several parameters of importance: a) Power output of laser being 10-3 to 10-1 Watts; b) Wavelength in the range of 300-10,600 nm; c) Pulse rate from 0, meaning continuous to 5000 Hertz (cycles per second); d) intensity of 10-2-10 W/cm(2) and dose of 0.01 to 100 J/cm2. Most common methods of administering LLL radiation include lasers such as ruby (694 nm), Ar (488 and 514 nm), He-Ne (632.8 nm), Krypton (521, 530, 568, and 647 nm), Ga-Al-As (805 or 650 nm), and Ga-As (904 nm). Perhaps one of the most distinguishing features of LLL therapy as compared to other photoceutical modalities is that effects are mediated not through induction of thermal effects but rather through a process that is still not clearly defined called "photobiostimulation". It appears that this effect of LLL is not depend on coherence, and therefore allows for use of non-laser light generating devices such as inexpensive Light Emitting Diode (LED) technology [28].

To date several mechanisms of biological action have been proposed, although none are clearly established. These include augmentation of cellular ATP levels [29], manipulation of inducible nitric oxide synthase (iNOS) activity [3031], suppression of inflammatory cytokines such as TNF-alpha, IL-1beta, IL-6 and IL-8 [3233343536], upregulation of growth factor production such as PDGF, IGF-1, NGF and FGF-2 [36373839], alteration of mitochondrial membrane potential [29404142] due to chromophores found in the mitochondrial respiratory chain [4344] as reviewed in [45], stimulation of protein kinase C (PKC) activation [46], manipulation of NF-κB activation [47], direct bacteriotoxic effect mediated by induction of reactive oxygen species (ROS) [48], modification of extracellular matrix components [49], inhibition of apoptosis [29], stimulation of mast cell degranulation [50], and upregulation of heat shock proteins [51]. Unfortunately these effects have been demonstrated using a variety of LLL devices in non-comparable models. To add to confusion, dose-dependency seems to be confined to such a narrow range or does not seem to exist in that numerous systems therapeutic effects disappear with increased dose.

In vitro studies of LLL

In areas of potential phenomenology, it is important to begin by assessing in vitro studies reported in the literature in which reproducibility can be attained with some degree of confidence, and mechanistic dissection is simpler as compared with in vivo systems. In 1983, one of the first studies to demonstrate in vitro effects of LLL was published. The investigators used a helium neon (He-Ne) laser to generate a visible red light at 632.8 nm for treatment of porcine granulosa cells. The paper described upregulation of metabolic and hormone-producing activity of the cells when exposed for 60 seconds to pulsating low power (2.8 mW) irradiation [52]. The possibility of modulating biologically-relevant signaling proteins by LLL was further assessed in a study using an energy dose of 1.5 J/cm2 in cultured keratinocytes. Administration of He-Ne laser emitted light resulted in upregulated gene expression of IL-1 and IL-8 [53]. Production of various growth factors in vitro suggests the possibility of enhanced cellular mitogenesis and mobility as a result of LLL treatment. Using a diode-based method to generate a similar wavelength to the He-Ne laser (363 nm), Mvula et al reported in two papers that irradiation at 5 J/cm2 of adipose derived mesenchymal stem cells resulted in enhanced proliferation, viability and expression of the adhesion molecule beta-1 integrin as compared to control [5455]. In agreement with possible regenerative activity based on activation of stem cells, other studies have used an in vitro injury model to examine possible therapeutic effects. Migration of fibroblasts was demonstrated to be enhanced in a "wound assay" in which cell monolayers are scraped with a pipette tip and amount of time needed to restore the monolayer is used as an indicator of "healing". The cells exposed to 5 J/cm2 generated by an He-Ne laser migrated rapidly across the wound margin indicating a stimulatory or positive influence of phototherapy. Higher doses (10 and 16 J/cm2) caused a decrease in cell viability and proliferation with a significant amount of damage to the cell membrane and DNA [56]. In order to examine whether LLL may positively affect healing under non-optimal conditions that mimic clinical situations treatment of fibroblasts from diabetic animals was performed. It was demonstrated that with the He-Ne laser dosage of 5 J/cm2 fibroblasts exhibited an enhanced migration activity, however at 16 J/cm2 activity was negated and cellular damage observed [57]. Thus from these studies it appears that energy doses from 1.5 J/cm2 to 5 J/cm2 are capable of eliciting "biostimulatory effects" in vitro in the He-Ne-based laser for adherent cells that may be useful in regeneration such as fibroblasts and mesenchymal stem cells.

Studies have also been performed in vitro on immunological cells. High intensity He-Ne irradiation at 28 and 112 J/cm2 of human peripheral blood mononuclear cells, a heterogeneous population of T cells, B cells, NK cells, and monocytes has been described to induce chromatin relaxation and to augment proliferative response to the T cell mitogen phytohemaglutin [58]. In human peripheral blood mononuclear cells (PBMC), another group reported in two papers that interleukin-1 alpha (IL-1 alpha), tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), and interferon-gamma (IFN-gamma) at a protein and gene level in PBMC was increased after He-Ne irradiation at 18.9 J/cm2 and decreased with 37.8 J/cm2 [5960]. Stimulation of human PBMC proliferation and murine splenic lymphocytes was also reported with He-Ne LLL [6162]. In terms of innate immune cells, enhanced phagocytic activity of murine macrophages have been reported with energy densities ranging from 100 to 600 J/cm2, with an optimal dose of 200 J/cm2 [63]. Furthermore, LLL has been demonstrated to augment human monocyte killing mycobacterial cells at similar densities, providing a functional correlation [64].

Thus from the selected in vitro studies discussed, it appears that modulation of proliferation and soluble factor production by LLL can be reliably reproduced. However the data may be to some extent contradictory. For example, the over-arching clinical rationale for use of LLL in conditions such as sinusitis [65], arthritis [6667], or wound healing [68] is that treatment is associated with anti-inflammatory effects. However the in vitro studies described above suggested LLL stimulates proinflammatory agents such as TNF-alpha or IL-1 [5960]. This suggests the in vivo effects of LLL may be very complex, which to some extent should not be surprising. Factors affecting LLL in vivo actions would include degree of energy penetration through the tissue, the various absorption ability of cells in the various tissues, and complex chemical changes that maybe occurring in paracrine/autocrine manner. Perhaps an analogy to the possible discrepancy between LLL effects in vitro versus in vivo may be made with the medical practice of extracorporeal ozonation of blood. This practice is similar to LLL therapy given that it is used in treatment of conditions such as atherosclerosis, non-healing ulcers, and various degenerative conditions, despite no clear mechanistic understanding [697071]. In vitro studies have demonstrated that ozone is a potent oxidant and inducer of cell apoptosis and inflammatory signaling [727374]. In contrast, in vivo systemic changes subsequent to administration of ozone or ozonized blood in animal models and patients are quite the opposite. Numerous investigators have published enhanced anti-oxidant enzyme activity such as elevations in Mg-SOD and glutathione-peroxidase levels, as well as diminishment of inflammation-associated pathology [75767778]. Regardless of the complexity of in vivo situations, the fact that reproducible, in vitro experiments, demonstrate a biological effect provided support for us that there is some basis for LLL and it is not strictly an area of phenomenology.

Animal Studies with LLL

As early as 1983, Surinchak et al reported in a rat skin incision healing model that wounds exposed He-Ne radiation of fluency 2.2 J/cm2 for 3 min twice daily for 14 days demonstrated a 55% increase in breaking strength over control rats. Interestingly, higher doses yielded poorer healing [79]. This application of laser light was performed directly on shaved skin. In a contradictory experiment, it was reported that rats irradiated for 12 days with four levels of laser light (0.0, 0.47, 0.93, and 1.73 J/cm2) a possible strengthening of wounds tension was observed at the highest levels of irradiation (1.73 J/cm2), however it did not reach significance when analyzed by resampling statistics [80]. In another wound-healing study Ghamsari et al reported accelerated healing in the cranial surface of teats in dairy cows by administration of He-Ne irradiation at 3.64 J/cm2 dose of low-level laser, using a helium-neon system with an output of 8.5 mW, continuous wave [81]. Collagen fibers in LLL groups were denser, thicker, better arranged and more continuous with existing collagen fibers than those in non-LLL groups. The mean tensile strength was significantly greater in LLL groups than in non-LLL groups [82]. In the random skin flap model, the use of He-Ne laser irradiation with 3 J/cm2 energy density immediately after the surgery and for the four subsequent days was evaluated in 4 experimental groups: Group 1 (control) sham irradiation with He-Ne laser; Group 2 irradiation by punctual contact technique on the skin flap surface; Group 3 laser irradiation surrounding the skin flap; and Group 4 laser irradiation both on the skin flap surface and around it. The percentage of necrotic area of the four groups was determined on day 7-post injury. The control group had an average necrotic area of 48.86%; the group irradiated on the skin flap surface alone had 38.67%; the group irradiated around the skin flap had 35.34%; and the group irradiated one the skin flap surface and around it had 22.61%. All experimental groups reached statistically significant values when compared to control [83]. Quite striking results were obtained in an alloxan-induced diabetes wound healing model in which a circular 4 cm2 excisional wound was created on the dorsum of the diabetic rats. Treatment with He-Ne irradiation at 4.8 J/cm2 was performed 5 days a week until the wound healed completely and compared to sham irradiated animals. The laser-treated group healed on average by the 18th day whereas, the control group healed on average by the 59th day [84].

In addition to mechanically-induced wounds, beneficial effects of LLL have been obtained in burn-wounds in which deep second-degree burn wounds were induced in rats and the effects of daily He-Ne irradiation at 1.2 and 2.4 J/cm2 were assessed in comparison to 0.2% nitrofurazone cream. The number of macrophages at day 16, and the depth of new epidermis at day 30, was significantly less in the laser treated groups in comparison with control and nitrofurazone treated groups. Additionally, infections with S. epidermidis and S. aureus were significantly reduced [85].

While numerous studies have examined dermatological applications of LLL, which may conceptually be easier to perform due to ability to topically apply light, extensive investigation has also been made in the area of orthopedic applications. Healing acceleration has been observed in regeneration of the rat mid-cortical diaphysis of the tibiae, which is a model of post-injury bone healing. A small hole was surgically made with a dentistry burr in the tibia and the injured area and LLL was administered over a 7 or 14 day course transcutaneously starting 24 h from surgery. Incident energy density dosages of 31.5 and 94.5 J/cm2 were applied during the period of the tibia wound healing. Increased angiogenesis was observed after 7 days irradiation at an energy density of 94.5 J/cm2, but significantly decreased the number of vessels in the 14-day irradiated tibiae, independent of the dosage [86]. In an osteoarthritis model treatment with He-Ne resulted in augmentation of heat shock proteins and pathohistological improvement of arthritic cartilage [87]. The possibility that a type of preconditioning response is occurring, which would involve induction of genes such as hemoxygenase-1 [88], remains to be investigated. Effects of LLL therapy on articular cartilage were confirmed by another group. The experiment consisted of 42 young Wistar rats whose hind limbs were operated on in order to immobilize the knee joint. One week after operation they were assigned to three groups; irradiance 3.9 W/cm2, 5.8 W/cm2, and sham treatment. After 6 times of treatment for another 2 weeks significantpreservation of articular cartilage stiffness with 3.9 and 5.8 W/cm2therapy was observed [89].

Muscle regeneration by LLL was demonstrated in a rat model of disuse atrophy in which eight-week-old rats were subjected to hindlimb suspension for 2 weeks, after which they were released and recovered. During the recovery period, rats underwent daily LLL irradiation (Ga-Al-As laser; 830 nm; 60 mW; total, 180 s) to the right gastrocnemius muscle through the skin. After 2-weeks the number of capillaries and fibroblast growth factor levels exhibited significant elevation relative to those of the LLL-untreated muscles. LLL treatment induced proliferation in satellite cells as detected by BRdU [90].

Other animal studies of LLL have demonstrated effects in areas that appear unrelated such as suppression of snake venom induced muscle death [91], decreasing histamine-induced vasospasms [92], inhibition of post-injury restenosis [93], and immune stimulation by thymic irradiation [94].

Clinical Studies Using LLL

Growth factor secretion by LLL and its apparent regenerative activities have stimulated studies in radiation-induced mucositis. A 30 patient randomized trial of carcinoma patients treated by radiotherapy alone (65 Gy at a rate of 2 Gy/fraction, 5 fractions per week) without prior surgery or concomitant chemotherapy suffering from radiation-induced mucositis was performed using a He-Ne 60 mW laser. Grade 3 mucositis occured with a frequency of 35.2% in controls and at 7.6% of treated patients. Furthermore, a decrease in "severe pain" (grade 3) was observed in that 23.8% in the control group experienced this level of pain, as compared to 1.9% in the treatment group [95]. A subsequent study reported similar effects [96].

Healing ability of lasers was also observed in a study of patients with gingival flap incisions. Fifty-eight extraction patients had one of two gingival flap incisions lased with a 1.4 mW He-Ne (670 nm) at 0.34 J/cm2. Healing rates were evaluated clinically and photographically. Sixty-nine percent of the irradiated incisions healed faster than the control incisions. No significant difference in healing was noted when patients were compared by age, gender, race, and anatomic location of the incision [97]. Another study evaluating healing effects of LLL in dental practice examined 48 patients subjected to surgical removal of their lower third molars. Treated patients were administered Ga-Al-As diode generated 808 nm at a dose of 12 J. The study demonstrated that extraoral LLL is more effective than intraoral LLL, which was more effective than control for the reduction of postoperative trismus and swelling after extraction of the lower third molar [98].

Given the predominance of data supporting fibroblast proliferative ability and animal wound healing effects of LLL therapy, a clinical trial was performed on healing of ulcers. In a double-blinded fashion 23 diabetic leg ulcers from 14 patients were divided into two groups. Phototherapy was applied (<1.0 J/cm2) twice per week, using a Dynatron Solaris 705(R) LED device that concurrently emits 660 and 890 nm energies. At days 15, 30, 45, 60, 75, and 90 mean ulcer granulation and healing rates were significantly higher for the treatment group as compared to control. By day 90, 58.3% of the ulcers in the LLL treated group were fully healed and 75% achieved 90-100% healing. In the placebo group only one ulcer healed fully [68].

As previously mentioned, LLL appears to have some angiogenic activity. One of the major problems in coronary artery disease is lack of collateralization. In a 39 patient study advanced CAD, two sessions of irradiation of low-energy laser light on skin in the chest area from helium-neon B1 lasers. The time of irradiation was 15 minutes while operations were performed 6 days a week for one month. Reduction in Canadian Cardiology Society (CCS) score, increased exercise capacity and time, less frequent angina symptoms during the treadmill test, longer distance of 6-minute walk test and a trend towards less frequent 1 mm ST depression lasting 1 min during Holter recordings was noted after therapy [99].

Perhaps one of the largest clinical trials with LLL was the NEST trial performed by Photothera. In this double blind trial 660 stroke patients were recruited and randomized: 331 received LLL and 327 received sham. No prespecified test achieved significance, but a post hoc analysis of patients with a baseline National Institutes of Health Stroke Scale score of <16 showed a favorable outcome at 90 days on the primary end point (P < 0.044) [100]. Currently Photothera is in the process of repeating this trial with modified parameters.

Relevance of LLL to COPD

A therapeutic intervention in COPD would require addressing the issues of inflammation and regeneration. Although approaches such as administration of bone marrow stem cells, or fat derived cellular components have both regenerative and anti-inflammatory activity in animal models, the need to enhance their potency for clinical applications can be seen in the recent Osiris's COPD trial interim data which reported no significant improvement in pulmonary function [101]. Accordingly, we sought to develop a possible rationale for how LLL may be useful as an adjunct to autologous stem cell therapy.

Table 1 depicts some of the properties of LLL that provide a rationale for the combined use with stem cells. One of the basic properties of LLL seems to be ability to inhibit inflammation at the level of innate immune activation. Representative studies showed that LLL was capable of suppressing inflammatory genes and/or pathology after administration of lipopolysaccharide (LPS) as a stimulator of monocytes [102] and bronchial cells [34], in vitro, and leukocyte infiltration in vivo [103104]. Inflammation induced by other stimulators such as zymosan, carrageenan, and TNF-alpha was also inhibited by LLL [32105106]. Growth factor stimulating activity of LLL was demonstrated in both in vitro and in vivo experiments in which augmentation of FGF-2, PDGF and IGF-1 was observed [3637107]. Endogenous production of these growth factors may be useful in regeneration based on activation of endogenous pulmonary stem cells [108109]. Another aspect of LLL activities of relevance is ability to stimulate angiogenesis. In COPD, the constriction of blood vessels as a result of poor oxygen uptake is results in a feedback loop culminating in pulmonary hypertension. Administration of angiogenic factors has been demonstrated to be beneficial in several animal models of pulmonary pathology [110111]. The ability of LLL to directly induce proliferation of HUVEC cells [112], as well as to augment production of angiogenic factors such as VEGF [113], supports the possibility of creation of an environment hospitable to neoangiogenesis which is optimal for stem cell growth. In fact, a study demonstrated in vivo induction of neocapillary formation subsequent to LLL administration in a hindlimb ischemia model [114]. The critical importance of angiogenesis in stem cell mediated regeneration has previously been demonstrated in the stroke model, where the major therapeutic activity of exogenous stem cells has been attributed to angiogenic as opposed to transdifferentiation effects [115].

 

 

Table 1

Examples of LLL Properties Relevant to COPD

COPD Property

LLL Experiment


Original Source: https://translational-medicine.biomedcentral.com/articles/10.1186/1479-5876-8-16

The effect of LED on blood microcirculation during chronic wound healing in diabetic and non-diabetic patients-a prospective, double-blind randomized study.

Frangez I, Cankar K, Ban Frangez H, Smrke DM. - Lasers Med Sci. 2017 May (Publication)
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Abstract

Chronic wounds, especially in diabetic patients, represent a challenging health issue. Since standard treatment protocols often do not provide satisfactory results, additional treatment methods—like phototherapy using low-level light therapy—are being investigated. The aim of our study was to evaluate the effect of phototherapy with light-emitting diodes on chronic wound treatment in diabetic and non-diabetic patients. Since a sufficient blood supply is mandatory for wound healing, the evaluation of microcirculation in the healthy skin at a wound’s edge was the main outcome measure. Forty non-diabetic patients and 39 diabetics with lower limb chronic wounds who were referred to the University Medical Center Ljubljana between October 2012 and June 2014 were randomized to the treated and control groups. The treated group received phototherapy with LED 2.4 J/cm2 (wavelengths 625, 660, 850 nm) three times a week for 8 weeks, and the control group received phototherapy with broadband 580–900 nm and power density 0.72 J/cm2. Microcirculation was measured using laser Doppler. A significant increase in blood flow was noted in the treated group of diabetic and non-diabetic patients (p = 0.040 and p = 0.033), while there was no difference in the control groups. Additional Falanga wound bed score evaluation showed a significant improvement in both treated groups as compared to the control group. According to our results, phototherapy with LED was shown to be an effective additional treatment method for chronic wounds in diabetic and non-diabetic patients.

Introduction

Chronic wounds—wounds that do not heal in months or even years—are one of the most persisting medical challenges because of their vast influence on public health [1, 2]. Standard treatment approaches including debridement of the necrotic tissue, maintenance of a moist wound bed, and control of the infection often do not produce the desired result. Wounds in patients with diabetes mellitus represent an even bigger problem since the healing process in these patients is known to be impaired [1].

Therefore, additional treatment options such as negative pressure dressings, hyperbaric oxygen therapy, topical application of carbon dioxide, and light therapy [3] are often employed. Light therapy has increasingly been investigated ever since Mester incidentally discovered that low-level laser therapy (LLLT) accelerated hair regrowth in laser-irradiated rats [4].

The effect of LLLT was first investigated in vitro to verify the influence of LLLT on cell proliferation [5, 6, 7]. Fibroblasts in cell cultures that were stimulated with LLLT proliferated significantly faster compared to sham-irradiated control cells [8, 9]. Other cell lines (gingival and mucosal fibroblasts, keratinocytes, osteoblasts, etc.) also showed faster proliferation if treated with LLLT [10, 11]. The next step in investigating LLLT was in vivo experiments on animals (mostly rats), which showed faster wound healing following LLLT [8, 10, 12]. The encouraging results of preclinical studies prompted the introduction of LLLT to different fields of medicine (wound healing, rheumatology, oral and sports medicine, etc.) [13, 14, 15, 16].

A recent survey critically reviewed eight clinical studies investigating the influence of LLLT on the healing of diabetic foot ulcers; all of the reviewed studies confirmed a beneficial effect of LLLT on the healing of diabetic ulcers [17].

Conversely, studies presenting data on LLLT and wound healing in general did not give such convincing conclusions. In his review in 2008, Sobanko concluded that LLLT in humans does not improve wound healing and advised better controlled studies in humans to determine the appropriate laser parameters and treatment protocol [18]. Kilik, on the other hand, confirmed that LLLT improved wound healing in normal and diabetic rats [1].

Wound healing in diabetic patients is probably impaired due to hyperglycemia, inhibition of inflammatory response, poor angiogenesis, fibroplasia and defects in collagen deposition, and differentiation of the extracellular matrix [1, 5].

The exact mechanism of low-power laser effect on tissue healing is not yet completely understood.

Studies have shown that LLLT accelerates the respiratory chain and increases reactive oxygen species (ROS), NO, and intracellular Ca2+ in stressed and hypoxic cells, but not in healthy cells [5, 19, 20]. Is it possible that the beneficial effect of LLLT on the wound-healing process in diabetic patients is more pronounced compared to non-diabetic patients because their cells are additionally hypoxic and stressed due to the diabetes itself?

The process of wound healing goes through the phases of inflammation, proliferation, and maturation [11]. A sufficient blood supply is mandatory for wound healing, but it is impaired in diabetic and non-diabetic patients with chronic wounds. This should be kept in mind when interpreting the results of published clinical studies.

The term LLLT was used for laser light only until the National Aeronautics and Space Administration (NASA) developed a new generation of light-emitting diodes (LEDs) to accelerate plant growth during space flights [21, 22]. Accelerated wound healing in astronauts treated with LED encouraged its use for medical purposes, and clinical experiences showed comparable results to LLLT [2, 21, 22, 23]. The abbreviation LLLT was later used for “low-level light therapy,” including low-level laser therapy or low-level light therapy using LED.

New generations of LED proved to be effective in wound healing if the right wavelengths, power density, and doses were used [24, 25]. In his review, Chaves compared the efficacy of low-level light therapy with laser and LED and concluded that both yielded similar biological effects, with no significant differences [2]. Light from lasers is coherent while light from LED is not; however, according to Karu, coherence is lost during the interaction of light with biological tissue and thus is not a prerequisite for the process of photostimulation or photoinhibition [26].

Results from previous studies evaluating the effect of LLLT on chronic wound healing in general are conflicting. In diabetic patients, LLLT was predominantly shown to be effective, whereas in non-diabetic patients, its benefits were not as pronounced. The aim of our study was to compare the influence of LLLT (using LED) as an additional therapy for chronic wound healing in diabetic and non-diabetic patients. Since a sufficient blood supply to the wound area is mandatory for healing, the microcirculation of the healthy skin on the wound margin was the main outcome measure of our study. Additionally, the wound bed score according to Falanga was evaluated [27].

Materials and methods

Patients

Eighty patients with chronic wound below the knee, with or without diabetes mellitus, who were referred to the University Medical Center Ljubljana between October 2012 and June 2014, were included in the study.

Patients were divided into diabetic and non-diabetic groups according to the presence of diabetes mellitus and further randomized into treated and non-treated subgroups (Fig. 1). Exclusion criteria included patients whose wound surface was too large (over 15 cm × 20 cm) or patients with wounds expanding to several planes where even distribution of the light at irradiation could not be guaranteed.

 

 

 

 

 

 

 

 

 

 

Fig. 1

Distribution and randomization of patients with below-knee chronic wounds.

One non-diabetic patient from the actively treated group failed to complete all applications of LED treatment due to personal reasons and was therefore excluded from the study.

All patients included in our study were referred to our clinic after their general practitioners failed to achieve satisfactory wound healing. The standard care provided by GPs includes taking care of the wound with wound dressings and occasionally with debridement of the necrotic tissue and antibiotic therapy. After examination, patients who met the inclusion criteria for our study immediately started with the standardized protocol.

All patients were treated according to common principles applied to the management of chronic wounds, including debridement of necrotic tissue, maintenance of a moist wound bed, and control of the infection.

Additionally, both treated groups received active therapy with LED and both control groups received therapy with light that simulated LED, but had no known biological effect (placebo). The study was double-blind.

LED therapy

The source of light therapy in our study was a LED, and not laser as in most previously mentioned studies.

The treated groups (D-LED and N-LED) received active therapy with LED (Ortholumm, Votan, Slovenia), and the control groups (D-Co and N-Co) received therapy with light that simulated LED—placebo (Table 1).

Table 1

Treatment regimes of active LED and placebo therapy

 

LED wavelengths (nm)

Total energy density (J/cm2) (time = 5 min)

Groups D-LED and N-LED (active)

625a, 660b, 850c

2.4 J/cm2 (24%a, 71%b, 5%c)

Groups D-Co and N-Co (placebo)

Broadband 580–900

0.72 J/cm2

a, b, cRepresent the contributing ratio of power density of corresponding wavelength

Actively LED-treated groups were irradiated with a mixture of three wavelengths. The contributing power density of each wavelength is shown in percentages in Table 1. The LED source was a square wave modulated at a frequency in the kilohertz range, with a 50% duty cycle.

Placebo groups were irradiated with broadband spectrum (automobile light bulbs were built into the same LED housing and red filters were added) with the same 5-min exposure time. In the placebo device, total energy is equally distributed between wavelengths 580 and 900 nm. This means that the energy of every wavelength is approximately 0.00225 J/cm2, which is 50 to 100 times less compared to the total energy densities in the active LED device. Therefore, we considered this to be placebo therapy.

The distance between the light source (LED or placebo) and the wound was 10 cm for all groups (Fig. 2).

 
 
Fig. 2

Ortholumm was used as a LED source (light source surface was approximately 88 cm2) at a distance of 10 cm, three times a week for 5 min. Treatment was performed for 8 weeks or, in the case of early healing, until wound closure.

Blood flow and Falanga wound bed evaluation

Blood analysis and microcirculation were evaluated using laser Doppler flow (LD flux) before the first treatment and at the end of the study.

Microcirculation was measured on the intact skin at wound border using laser Doppler (LD) flux sensors (Angled probe 401, Perimed, Järfälla, Sweden) together with laser light sources at 780 nm (PF 4001 and PF 4002 Satelite, Perimed, Järfälla, Sweden).

Patients were scheduled for wound management and LED/placebo treatment three times a week. Wound status according to Falanga wound bed score (Table 2) was evaluated before the first treatment and every 2 weeks.

 

Table 2

Falanga wound bed evaluation score [27]

Falanga score

Granulation

Fibrinous

Eschar

A

100%

B

50–100%

+

C

<50%

+

D

Any amount

+

+

Statistical analysis

For statistical analysis, a paired T test or chi-square test was performed to compare the variables before and after treatment and between groups. The mean differences and 95% confidence intervals (95% CI) were calculated with two-sided probability (p) values. Significance level was set at p < 0.05. Statistical analysis was performed using IBM SPSS Statistics, v. 19 (IBM Corp, Armonk, NY).

Results

Age and sex distribution as well as wound surface and wound persistence in months were comparable in all four subgroups (Table 3). There were some expected differences between diabetic and non-diabetic patients: diabetic patients had higher BMI, higher fasting glucose levels, higher levels of CRP, and lower hemoglobin values (Table 4).

 

Table 3

Group description—basic data

 

Group D-LED (n = 20)

Group D-Co (n = 20)

Group N-LED (n = 19)

Group N-Co (n = 20)

Male/female

17/3

14/6

13/6

16/4

Age (mean ± SD)

61.15 ± 8.77

65.45 ± 9.57

63.84 ± 16.34

62.8 ± 11.88

BMI (mean ± SD)

30.72 ± 5.45

29.30 ± 4.65a

28.15 ± 5.65

26.58 ± 3.67a

Wound persistence in months (mean ± SD)

8.1 ± 6.13

9.15 ± 10.72

9.58 ± 16.76

9.4 ± 16.35

Wound surface in mm2 (mean ± SD)

842 ± 74.22

978.21 ± 222.38

912.5 ± 110.89

814 ± 120.01

BMI body mass index

Only significant differences for p < 0.05 are shown: a p = 0.04

 

Table 4

Group description—main blood analysis results before wound treatment

 

Group D-LED (n = 20)

Group D-Co (n = 20)

Group N-LED (n = 19)

Group N-Co (n = 20)

p value

Fasting glucose level (mean ± SD)

7.8 ± 4.5a

8.86 ± 4.0b

5.6 ± 0.8a

5.6 ± 2.0b

a0.032

b0.003

Elevated CRP

13/20c

11/20

6/19c

9/20

c0.001

Hemoglobin (mean ± SD)

127.1 ± 13.9d

126.8 ± 14.9e

140.7 ± 16.5d

144.3 ± 14.1e

d0.008

e0.001

Fibrinogen (mean ± SD)

4.63 ± 1.04

4.67 ± 1.57

3.97 ± 1.05

4.11 ± 1.11

 

CRP C-reactive protein

Only significant differences for p < 0.05 are shown

a, b, c, d, eRepresent the p value of the compared corresponding values

Blood flow measured with LD flux revealed significantly increased microcirculation in LED-treated groups and no difference in control groups (Fig. 3).
Fig. 3

Mean blood flow measured with LD flux before and after 8 weeks of therapy. In LED-treated groups, a significant increase in blood flow was noted (*p = 0.040 and **p = 0.033). There was no difference in control groups.

 

Falanga wound bed evaluation showed significantly faster granulation and healing of the wound bed in both LED-treated groups compared to control groups (Fig. 4).
Fig. 4

ad The Falanga wound bed score in all groups evaluated every 2 weeks. Before LED therapy (week 0), there was no difference in Falanga score between D-LED and D-Co (p = ns), or between N-LED and N-Co (p = ns). After 8 weeks of treatment, a significant improvement was seen in wound bed granulation (Falanga score A) in both LED-treated groups; D-LED vs. D-Co, p = 0.0005; N-LED vs. N-Co, p = 0.0014

Blood analysis after 8 weeks of treatment showed no difference in fasting glucose levels, fibrinogen, hemoglobin, and SR in any of the groups. Figure 5 shows wounds of two patients from LED-treated groups.
Fig. 5

A 70-year-old female without diabetes that had a persisting wound for 7 months due to peripheral arterial occlusive disease (a). The wound was partially healed after 8 weeks of LED therapy (b). A 58-year-old male with diabetes and a posttraumatic wound that persisted for 3 months (c). After 5 weeks of LED therapy, the wound was completely healed (d)

Discussion

Wound healing is a complex process involving inflammation, proliferation, and maturation of the newly formed tissue [3, 28]. Wounds normally heal in 6–8 weeks or, in cases of larger or deeper wounds, they at least start healing by that time. If the process of healing is interrupted or impaired due to an infection or other causes (poor vascularization, malnutrition, diabetes, etc.), the wound does not heal and it becomes a chronic wound [28].

A standard approach to chronic wound treatment includes debridement of the necrotic tissue, use of wound dressings that maintain a moist wound bed, and control of the infection. Chronic wounds, however, are predominantly infected. In cases where a chronic wound is not infected, a surgical approach like skin grafting can successfully be applied.

Another condition that has to be fulfilled in order for a wound to start healing is sufficient blood supply to the wound area. The prognosis of chronic wounds on lower limbs of patients with peripheral angiopathy (not related to the coexistence of diabetes) is directly related to the quality of blood supply to the wound area. Therefore, in cases where healing is impaired due to insufficient blood supply, the possibility of a vascular bypass or endovascular therapy should be considered [29].

A clinical approach to the treatment of chronic wounds includes different aspects. According to our study results, low-level light therapy with LED has a beneficial effect if used with the right indications.

We evaluated the effect of LED predominantly by measuring the improvement in blood microcirculation using laser Doppler flowmetry. Wound status according to the Falanga wound bed score was also evaluated [27]. Results revealed a significant improvement in wound healing in LED-treated groups according to the Falanga score. Chronic wounds in our research differed in size and depth. Shrinkage of the wound surface during the healing process depends on wound depth; that is why we decided that wound surface would not be the main outcome measure in our study. Falanga wound bed score was also evaluated in our study, but as it is subjective and based on the morphologic appearance of the wound, we looked for a clinically important parameter that could be objectively measured.

Laser Doppler flowmetry (LD flow) provides a non-invasive method for assessing cutaneous perfusion. Skin perfusion measurements using the laser Doppler technique depend on how the light interacts with the moving blood cells and static tissue [30]. In our study, all patients had LD flow measured by the same physician. Measurements were performed before the first LED treatment and after 8 weeks of treatment with LED, on the same area of the intact skin at the wound border.

Study results have shown that microcirculation improved in both groups of patients, diabetics and non-diabetics treated with active LED, as compared to the placebo control groups. The healing process according to the Falanga wound bed score was faster in diabetics and non-diabetics treated with active LED as compared to the control groups.

According to our results, treatment of chronic wounds with LED, if used as an adjuvant therapy to all standard treatment approaches, is effective in diabetic and non-diabetic patients.

Based on previous clinical study results of LLLT in the treatment of diabetic foot ulcers, a beneficial effect was expected. Beckmann reviewed eight randomized clinical trials that all showed an improvement of the wound-healing process according to the main outcome measures that were directly or indirectly associated with wound healing [17]. In our study, the beneficial effect of LED treatment was also seen: the microcirculation and Falanga wound bed status improved after 8 weeks of LED treatment despite the fact that the LED power density used in our study was significantly lower than in most previous studies.

According to Huang and his theory, a negative impact should be expected with higher energy densities used, which is why we decided to use lower doses [31]. But according to Landau, who used 43.2 J/cm2, and some other reports, healing was importantly enhanced also with much higher energy densities [32, 33, 34]. Considering our results and previous study results, the question that arises is as follows: are low energy doses really the most effective or can ineffectiveness in some reports be explained with the use of a dose that was too low? It is known that the total irradiation dose is often impossible to calculate due to a lack of the description of LLLT parameters. Perhaps, wounds of different etiologies require different treatment regimes and leprosy ulcers that did not respond to 2–4 J/cm2 would exhibit better healing results with higher doses [35]? Or perhaps the reason for a low effect of LLLT in some reports was that only the wound bed and the edges were treated with sources that have a small surface of light beam? In our research, the entire wound area and its surroundings were treated and microcirculation in the healthy skin at wound edge was improved. This means that the blood supply to the wound improved, which is very important because a sufficient blood supply is mandatory for wound healing.

Conclusion

The use of LED as an adjuvant therapy resulted in improved microcirculation and Falanga wound bed score in chronic wound treatment.

 

References

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Original Source: https://www.ncbi.nlm.nih.gov/pubmed/28342007

Effect of laser therapy on skeletal muscle repair process in diabetic rats.

França CM1, de Loura Santana C, Takahashi CB, Alves AN, De Souza Mernick AP, Fernandes KP, de Fátima Teixeira da Silva D, Bussadori SK, Mesquita-Ferrari RA. - Lasers Med Sci. 2013 Sep;28(5):1331-8. doi: 10.1007/s10103-012-1249-2. Epub 2012 Dec 22. (Publication)
This study used the Microlight ML830 with just 90mW of power. Even at this extremely low power, the acheived good results in treating diabetic mice.
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Intro: Skeletal muscle myopathy is a common source of disability in diabetic patients. This study evaluated whether low-level laser therapy (LLLT) influences the healing morphology of injured skeletal muscle. Sixty-five male Wistar rats were divided as follows: (1) sham; (2) control; (3) diabetic; (4) diabetic sham; (5) nondiabetic cryoinjured submitted to LLLT (LLLT); (6) diabetic cryoinjured submitted to LLLT (D-LLLT); and (7) diabetic cryoinjured non-treated (D). Diabetes was induced with streptozotocin. Anterior tibialis muscle was cryoinjured and received LLLT daily (780 nm, 5 J/cm(2), 10 s per point; 0.2 J; total treatment, 1.6 J). Euthanasia occurred on day 1 in groups 1, 2, 3, and 4 and on days 1, 7, and 14 in groups 5, 6, and 7. Muscle samples were processed for H&E and Picrosirius Red and photographed. Leukocytes, myonecrosis, fibrosis, and immature fibers were manually quantified using the ImageJ software. On day 1, all cryoinjured groups were in the inflammatory phase. The D group exhibited more myonecrosis than LLLT group (p < 0.05). On day 14, the LLLT group was in the remodeling phase; the D group was still in the proliferative phase, with fibrosis, chronic inflammation, and granulation tissue; and the D-LLLT group was in an intermediary state in relation to the two previous groups. Under polarized light, on day 14, the LLLT and D-LLLT groups had organized collagen bundles in the perimysium, whereas the diabetic groups exhibited fibrosis. LLLT can have a positive effect on the morphology of skeletal muscle during the tissue repair process by enhancing the reorganization of myofibers and the perimysium, reducing fibrosis.

Background: Skeletal muscle myopathy is a common source of disability in diabetic patients. This study evaluated whether low-level laser therapy (LLLT) influences the healing morphology of injured skeletal muscle. Sixty-five male Wistar rats were divided as follows: (1) sham; (2) control; (3) diabetic; (4) diabetic sham; (5) nondiabetic cryoinjured submitted to LLLT (LLLT); (6) diabetic cryoinjured submitted to LLLT (D-LLLT); and (7) diabetic cryoinjured non-treated (D). Diabetes was induced with streptozotocin. Anterior tibialis muscle was cryoinjured and received LLLT daily (780 nm, 5 J/cm(2), 10 s per point; 0.2 J; total treatment, 1.6 J). Euthanasia occurred on day 1 in groups 1, 2, 3, and 4 and on days 1, 7, and 14 in groups 5, 6, and 7. Muscle samples were processed for H&E and Picrosirius Red and photographed. Leukocytes, myonecrosis, fibrosis, and immature fibers were manually quantified using the ImageJ software. On day 1, all cryoinjured groups were in the inflammatory phase. The D group exhibited more myonecrosis than LLLT group (p < 0.05). On day 14, the LLLT group was in the remodeling phase; the D group was still in the proliferative phase, with fibrosis, chronic inflammation, and granulation tissue; and the D-LLLT group was in an intermediary state in relation to the two previous groups. Under polarized light, on day 14, the LLLT and D-LLLT groups had organized collagen bundles in the perimysium, whereas the diabetic groups exhibited fibrosis. LLLT can have a positive effect on the morphology of skeletal muscle during the tissue repair process by enhancing the reorganization of myofibers and the perimysium, reducing fibrosis.

Abstract: Abstract Skeletal muscle myopathy is a common source of disability in diabetic patients. This study evaluated whether low-level laser therapy (LLLT) influences the healing morphology of injured skeletal muscle. Sixty-five male Wistar rats were divided as follows: (1) sham; (2) control; (3) diabetic; (4) diabetic sham; (5) nondiabetic cryoinjured submitted to LLLT (LLLT); (6) diabetic cryoinjured submitted to LLLT (D-LLLT); and (7) diabetic cryoinjured non-treated (D). Diabetes was induced with streptozotocin. Anterior tibialis muscle was cryoinjured and received LLLT daily (780 nm, 5 J/cm(2), 10 s per point; 0.2 J; total treatment, 1.6 J). Euthanasia occurred on day 1 in groups 1, 2, 3, and 4 and on days 1, 7, and 14 in groups 5, 6, and 7. Muscle samples were processed for H&E and Picrosirius Red and photographed. Leukocytes, myonecrosis, fibrosis, and immature fibers were manually quantified using the ImageJ software. On day 1, all cryoinjured groups were in the inflammatory phase. The D group exhibited more myonecrosis than LLLT group (p < 0.05). On day 14, the LLLT group was in the remodeling phase; the D group was still in the proliferative phase, with fibrosis, chronic inflammation, and granulation tissue; and the D-LLLT group was in an intermediary state in relation to the two previous groups. Under polarized light, on day 14, the LLLT and D-LLLT groups had organized collagen bundles in the perimysium, whereas the diabetic groups exhibited fibrosis. LLLT can have a positive effect on the morphology of skeletal muscle during the tissue repair process by enhancing the reorganization of myofibers and the perimysium, reducing fibrosis.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23262549

Irradiation at 830 nm stimulates nitric oxide production and inhibits pro-inflammatory cytokines in diabetic wounded fibroblast cells.

Houreld NN1, Sekhejane PR, Abrahamse H. - Lasers Surg Med. 2010 Aug;42(6):494-502. doi: 10.1002/lsm.20812. (Publication)
Even very low dosages of just 5j/cm has a positive effect on wound healing in vitro.
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Intro: Wound healing in diabetic patients remains a chief problem in the clinical setting and there is a strong need for the development of new, safe, reliable therapies. This study aimed to establish the effect of irradiating diabetic wounded fibroblast cells (WS1) in vitro on pro-inflammatory cytokines and the production of nitric oxide (NO).

Background: Wound healing in diabetic patients remains a chief problem in the clinical setting and there is a strong need for the development of new, safe, reliable therapies. This study aimed to establish the effect of irradiating diabetic wounded fibroblast cells (WS1) in vitro on pro-inflammatory cytokines and the production of nitric oxide (NO).

Abstract: Abstract BACKGROUND AND OBJECTIVE: Wound healing in diabetic patients remains a chief problem in the clinical setting and there is a strong need for the development of new, safe, reliable therapies. This study aimed to establish the effect of irradiating diabetic wounded fibroblast cells (WS1) in vitro on pro-inflammatory cytokines and the production of nitric oxide (NO). MATERIALS AND METHODS: Normal, wounded and diabetic wounded WS1 cells were exposed to an 830 nm laser with 5 J/cm(2) and incubated for a pre-determined amount of time. Changes in cellular viability, proliferation and apoptosis were evaluated by the Trypan blue assay, VisionBlue fluorescence assay and caspase 3/7 activity respectively. Changes in cytokines (interleukin--IL-6, IL-1 beta and tumour necrosis factor-alpha, TNF-alpha) were determined by ELISA. NO was determined spectrophotometrically and reactive oxygen species (ROS) was evaluated by immunofluorescent staining. RESULTS: Diabetic wounded WS1 cells showed no significant change in viability, a significant increase in proliferation at 24 and 48 hours (P<0.001 and P<0.01 respectively) and a decrease in apoptosis 24 hours post-irradiation (P<0.01). TNF-alpha levels were significantly decreased at both 1 and 24 hours (P<0.05), while IL-1 beta was only decreased at 24 hours (P<0.05). There was no significant change in IL-6. There was an increase in ROS and NO (P<0.01) 15 minutes post-irradiation. CONCLUSION: Results show that irradiation of diabetic wounded fibroblast cells at 830 nm with 5 J/cm(2) has a positive effect on wound healing in vitro. There was a decrease in pro-inflammatory cytokines (IL-1 beta and TNF-alpha) and irradiation stimulated the release of ROS and NO due to what appears to be direct photochemical processes. (c) 2010 Wiley-Liss, Inc.

Methods: Normal, wounded and diabetic wounded WS1 cells were exposed to an 830 nm laser with 5 J/cm(2) and incubated for a pre-determined amount of time. Changes in cellular viability, proliferation and apoptosis were evaluated by the Trypan blue assay, VisionBlue fluorescence assay and caspase 3/7 activity respectively. Changes in cytokines (interleukin--IL-6, IL-1 beta and tumour necrosis factor-alpha, TNF-alpha) were determined by ELISA. NO was determined spectrophotometrically and reactive oxygen species (ROS) was evaluated by immunofluorescent staining.

Results: Diabetic wounded WS1 cells showed no significant change in viability, a significant increase in proliferation at 24 and 48 hours (P<0.001 and P<0.01 respectively) and a decrease in apoptosis 24 hours post-irradiation (P<0.01). TNF-alpha levels were significantly decreased at both 1 and 24 hours (P<0.05), while IL-1 beta was only decreased at 24 hours (P<0.05). There was no significant change in IL-6. There was an increase in ROS and NO (P<0.01) 15 minutes post-irradiation.

Conclusions: Results show that irradiation of diabetic wounded fibroblast cells at 830 nm with 5 J/cm(2) has a positive effect on wound healing in vitro. There was a decrease in pro-inflammatory cytokines (IL-1 beta and TNF-alpha) and irradiation stimulated the release of ROS and NO due to what appears to be direct photochemical processes.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/20662026

Influence of ingaalp laser (660nm) on the healing of skin wounds in diabetic rats.

Carvalho Pde T1, Silva IS, Reis FA, Perreira DM, Aydos RD. - Acta Cir Bras. 2010 Feb;25(1):71-9. (Publication)
The low-power 4 j/cm laser (660 nm) was shown to be capable of influencing the collagen percentage in skin wounds by increasing the mean quantity of collagen fibers and macrophages.
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Intro: To determine the influence of low-power laser (660 nm) on the collagen percentage and macrophages in skin wounds in diabetic rats.

Background: To determine the influence of low-power laser (660 nm) on the collagen percentage and macrophages in skin wounds in diabetic rats.

Abstract: Abstract PURPOSE: To determine the influence of low-power laser (660 nm) on the collagen percentage and macrophages in skin wounds in diabetic rats. METHODS: 30 male Wistar rats were used, distributed in two groups: laser treated diabetic (n= 15); untreated diabetic (n = 15). The diabetes was induced by intravenous injection of alloxan into the dorsal vein of the penis, at a rate of 0.1 ml of solution per 100 g of body weight. A wound was made on the back of all the animals. Groups 2 were treated with Aluminium Gallium Indium Phosphide - InGaAlP type diode laser (Photon Laser III DMC) with a continuous output power of 100 mW and wavelength (lambda) of 660 nm (4 J/cm(2)) for 24 s. five animal from each group was sacrificed on the 3rd, 7th and 14th days after wounding. Samples were taken, embedded in paraffin, stained with hematoxylin-eosin, Masson's trichrome, and immunohistochemical macrophage. morphometrically analyzed using the Image Pro Plus 4.5 software. The percentages of collagen fibers and macrophages were determined from the samples from the euthanasia animals. RESULTS: The data were treated statistically using analysis of variance (ANOVA) and the Post-hocTukey test. The significance level was set at 0.05 or 5%. CONCLUSION: The low-power laser (660 nm) was shown to be capable of influencing the collagen percentage in skin wounds by increasing the mean quantity of collagen fibers and macrophages.

Methods: 30 male Wistar rats were used, distributed in two groups: laser treated diabetic (n= 15); untreated diabetic (n = 15). The diabetes was induced by intravenous injection of alloxan into the dorsal vein of the penis, at a rate of 0.1 ml of solution per 100 g of body weight. A wound was made on the back of all the animals. Groups 2 were treated with Aluminium Gallium Indium Phosphide - InGaAlP type diode laser (Photon Laser III DMC) with a continuous output power of 100 mW and wavelength (lambda) of 660 nm (4 J/cm(2)) for 24 s. five animal from each group was sacrificed on the 3rd, 7th and 14th days after wounding. Samples were taken, embedded in paraffin, stained with hematoxylin-eosin, Masson's trichrome, and immunohistochemical macrophage. morphometrically analyzed using the Image Pro Plus 4.5 software. The percentages of collagen fibers and macrophages were determined from the samples from the euthanasia animals.

Results: The data were treated statistically using analysis of variance (ANOVA) and the Post-hocTukey test. The significance level was set at 0.05 or 5%.

Conclusions: The low-power laser (660 nm) was shown to be capable of influencing the collagen percentage in skin wounds by increasing the mean quantity of collagen fibers and macrophages.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/20126892

Effectiveness of laser photobiomodulation at 660 or 780 nanometers on the repair of third-degree burns in diabetic rats.

Meireles GC1, Santos JN, Chagas PO, Moura AP, Pinheiro AL. - Photomed Laser Surg. 2008 Feb;26(1):47-54. doi: 10.1089/pho.2007.2051. (Publication)
This study indicates that 660 nm (RED) is superior for burn healing when compared to 780nm (IR) and both were superior to no laser.
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Intro: The aim of this investigation was to compare by light microscopy the effects of laser photobiomodulation (LPBM) at lambda = 660 nm and lambda = 780 nm on third-degree burns in diabetic Wistar rats.

Background: The aim of this investigation was to compare by light microscopy the effects of laser photobiomodulation (LPBM) at lambda = 660 nm and lambda = 780 nm on third-degree burns in diabetic Wistar rats.

Abstract: Abstract OBJECTIVE: The aim of this investigation was to compare by light microscopy the effects of laser photobiomodulation (LPBM) at lambda = 660 nm and lambda = 780 nm on third-degree burns in diabetic Wistar rats. BACKGROUND DATA: Burns are severe injuries that result in fluid loss, tissue destruction, infection, and shock, that may result in death. Diabetes is a disease that reduces the body's ability to heal properly. LPBM has been suggested as an effective method of improving wound healing. MATERIALS AND METHODS: A third-degree burn measuring 1.5 x 1.5 cm was created in the dorsum of each of 55 animals, and they were divided into three groups that were or were not treated with LPBM (lambda = 660 nm or lambda = 780 nm, 35 mW, varphi = 2 mm, 20 J/cm(2)). The treatments were started immediately post-burn at four points within the burned area (5 J/cm(2)) and were repeated at 24-hour intervals over 21 d. The animals were humanely killed after 3, 5, 7, 14, and 21 d by an overdose of intraperitoneal general anesthetic. The specimens were routinely cut and stained and analyzed by light microscopy. RESULTS: We found that healing in the animals receiving 660-nm laser energy was more apparent at early stages, with positive effects on inflammation, the amount and quality of granulation tissue, fibroblast proliferation, and on collagen deposition and organization. Epithelialization and local microcirculation were also positively affected by the treatment. CONCLUSION: The use of 780-nm laser energy was not as effective as 660-nm energy, but it had positive effects at early stages on the onset and development of inflammation. At the end of the experimental period the primary effect seen was on the amount and quality of the granulation tissue. The 660-nm laser at 20 J/cm(2), when used on a daily basis, was more effective than the 780-nm laser for improving the healing of third-degree burns in the diabetic rats beginning at the early stages post-burn.

Methods: Burns are severe injuries that result in fluid loss, tissue destruction, infection, and shock, that may result in death. Diabetes is a disease that reduces the body's ability to heal properly. LPBM has been suggested as an effective method of improving wound healing.

Results: A third-degree burn measuring 1.5 x 1.5 cm was created in the dorsum of each of 55 animals, and they were divided into three groups that were or were not treated with LPBM (lambda = 660 nm or lambda = 780 nm, 35 mW, varphi = 2 mm, 20 J/cm(2)). The treatments were started immediately post-burn at four points within the burned area (5 J/cm(2)) and were repeated at 24-hour intervals over 21 d. The animals were humanely killed after 3, 5, 7, 14, and 21 d by an overdose of intraperitoneal general anesthetic. The specimens were routinely cut and stained and analyzed by light microscopy.

Conclusions: We found that healing in the animals receiving 660-nm laser energy was more apparent at early stages, with positive effects on inflammation, the amount and quality of granulation tissue, fibroblast proliferation, and on collagen deposition and organization. Epithelialization and local microcirculation were also positively affected by the treatment.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/18248161

The effect of red, green and blue lasers on healing of oral wounds in diabetic rats.

Fekrazad R1, Mirmoezzi A2, Kalhori KA3, Arany P4. - J Photochem Photobiol B. 2015 Jul;148:242-5. doi: 10.1016/j.jphotobiol.2015.04.018. Epub 2015 May 1. ()
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Intro: Many studies have demonstrated that low-level laser therapy (LLLT) can improve wound healing in non-diabetic and diabetic animals. We compared the effects of red, green, and blue lasers in terms of accelerating oral wound healing in diabetic rats.

Background: Many studies have demonstrated that low-level laser therapy (LLLT) can improve wound healing in non-diabetic and diabetic animals. We compared the effects of red, green, and blue lasers in terms of accelerating oral wound healing in diabetic rats.

Abstract: Abstract BACKGROUND AND OBJECTIVE: Many studies have demonstrated that low-level laser therapy (LLLT) can improve wound healing in non-diabetic and diabetic animals. We compared the effects of red, green, and blue lasers in terms of accelerating oral wound healing in diabetic rats. MATERIAL AND METHODS: Diabetes was successfully induced in 32 male Wistar rats using intraperitoneal injection of Streptozotocin (150 mg/kg). After intraperitoneal injection of the anesthetic agent, a full-thickness oral wound (10 mm × 2 mm) was created aseptically with a scalpel on hard palate of the diabetic rats. The study was performed using red (630 nm), green (532 nm), and blue (425 nm) lasers and a control group. We used an energy density of 2J/cm2 and a treatment schedule of 3 times/week for 10 days. The area of wounds was measured and recorded on a chart for all rats. On the 10th day, the samples were then sacrificed and a full-thickness sample of wound area was prepared for pathological study. RESULTS: We observed a significant difference (p<0.001) in the mean slope values of wound healing between treatment and control groups. Moreover, the mean slope of wound healing differed significantly between red laser and two other lasers - blue and green (p<0.001). The mean slopes of wound healing were not significantly different between blue laser and green laser (p=0.777). CONCLUSION: The results of the present study provide evidence that wound healing is slower in control rats compared to the treatment groups. Moreover, the findings suggest that wound healing occurs faster with red laser compared to blue and green lasers. Copyright © 2015 Elsevier B.V. All rights reserved.

Methods: Diabetes was successfully induced in 32 male Wistar rats using intraperitoneal injection of Streptozotocin (150 mg/kg). After intraperitoneal injection of the anesthetic agent, a full-thickness oral wound (10 mm × 2 mm) was created aseptically with a scalpel on hard palate of the diabetic rats. The study was performed using red (630 nm), green (532 nm), and blue (425 nm) lasers and a control group. We used an energy density of 2J/cm2 and a treatment schedule of 3 times/week for 10 days. The area of wounds was measured and recorded on a chart for all rats. On the 10th day, the samples were then sacrificed and a full-thickness sample of wound area was prepared for pathological study.

Results: We observed a significant difference (p<0.001) in the mean slope values of wound healing between treatment and control groups. Moreover, the mean slope of wound healing differed significantly between red laser and two other lasers - blue and green (p<0.001). The mean slopes of wound healing were not significantly different between blue laser and green laser (p=0.777).

Conclusions: The results of the present study provide evidence that wound healing is slower in control rats compared to the treatment groups. Moreover, the findings suggest that wound healing occurs faster with red laser compared to blue and green lasers.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/25981185

Tissue responses to postoperative laser therapy in diabetic rats submitted to excisional wounds.

de Loura Santana C1, Silva Dde F1, Deana AM1, Prates RA1, Souza AP1, Gomes MT1, de Azevedo Sampaio BP1, Shibuya JF1, Bussadori SK1, Mesquita-Ferrari RA1, Fernandes KP1, França CM1. - PLoS One. 2015 Apr 24;10(4):e0122042. doi: 10.1371/journal.pone.0122042. eCollection 2015. ()
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Intro: In a previous study about low-level laser therapy biomodulation on a full-thickness burn model we showed that single and fractionated dose regimens increased wound healing and leukocyte influx similarly when compared with untreated control. In order to verify if this finding would be similar in an impaired wound model, we investigated the effect of single and multiple irradiations on wound closure rate, type of inflammatory infiltrate, myofibroblasts, collagen deposition, and optical retardation of collagen in diabetic rats. Female Wistar rats in the same estrous cycle had diabetes induced with streptozotocin and an 8-mm excisional wound performed with a punch. The experimental groups were: control group--untreated ulcer; single-dose group--ulcer submitted to single dose of diode laser therapy (λ = 660 ± 2 nm; P = 30 mW; energy density: 4 J/cm2) and fractionated-dose group--ulcer submitted to 1 J/cm2 laser therapy on Days 1, 3, 8, and 10. The ulcers were photographed on the experimental days and after euthanasia tissue samples were routinely processed for histological and immunohistochemistry analyses. Independently of the energy density, laser therapy accelerated wound closure by approximately 40% in the first three days in comparison to the control group. Laser therapy increased acute inflammatory infiltrate until Day 3. Both laser groups exhibited more myofibroblasts and better collagen organization than the control group. The findings demonstrate that low-level laser therapy in the immediate postoperative period can enhance the tissue repair process in a diabetes model. Similar effects were achieved with laser therapy applied a single time with an energy density of 4 J/cm2 and applied four times with an energy density of 1 J/cm2. The application of laser therapy in the inflammatory phase was the most important factor to the enhancement of the tissue repair process.

Background: In a previous study about low-level laser therapy biomodulation on a full-thickness burn model we showed that single and fractionated dose regimens increased wound healing and leukocyte influx similarly when compared with untreated control. In order to verify if this finding would be similar in an impaired wound model, we investigated the effect of single and multiple irradiations on wound closure rate, type of inflammatory infiltrate, myofibroblasts, collagen deposition, and optical retardation of collagen in diabetic rats. Female Wistar rats in the same estrous cycle had diabetes induced with streptozotocin and an 8-mm excisional wound performed with a punch. The experimental groups were: control group--untreated ulcer; single-dose group--ulcer submitted to single dose of diode laser therapy (λ = 660 ± 2 nm; P = 30 mW; energy density: 4 J/cm2) and fractionated-dose group--ulcer submitted to 1 J/cm2 laser therapy on Days 1, 3, 8, and 10. The ulcers were photographed on the experimental days and after euthanasia tissue samples were routinely processed for histological and immunohistochemistry analyses. Independently of the energy density, laser therapy accelerated wound closure by approximately 40% in the first three days in comparison to the control group. Laser therapy increased acute inflammatory infiltrate until Day 3. Both laser groups exhibited more myofibroblasts and better collagen organization than the control group. The findings demonstrate that low-level laser therapy in the immediate postoperative period can enhance the tissue repair process in a diabetes model. Similar effects were achieved with laser therapy applied a single time with an energy density of 4 J/cm2 and applied four times with an energy density of 1 J/cm2. The application of laser therapy in the inflammatory phase was the most important factor to the enhancement of the tissue repair process.

Abstract: Abstract In a previous study about low-level laser therapy biomodulation on a full-thickness burn model we showed that single and fractionated dose regimens increased wound healing and leukocyte influx similarly when compared with untreated control. In order to verify if this finding would be similar in an impaired wound model, we investigated the effect of single and multiple irradiations on wound closure rate, type of inflammatory infiltrate, myofibroblasts, collagen deposition, and optical retardation of collagen in diabetic rats. Female Wistar rats in the same estrous cycle had diabetes induced with streptozotocin and an 8-mm excisional wound performed with a punch. The experimental groups were: control group--untreated ulcer; single-dose group--ulcer submitted to single dose of diode laser therapy (λ = 660 ± 2 nm; P = 30 mW; energy density: 4 J/cm2) and fractionated-dose group--ulcer submitted to 1 J/cm2 laser therapy on Days 1, 3, 8, and 10. The ulcers were photographed on the experimental days and after euthanasia tissue samples were routinely processed for histological and immunohistochemistry analyses. Independently of the energy density, laser therapy accelerated wound closure by approximately 40% in the first three days in comparison to the control group. Laser therapy increased acute inflammatory infiltrate until Day 3. Both laser groups exhibited more myofibroblasts and better collagen organization than the control group. The findings demonstrate that low-level laser therapy in the immediate postoperative period can enhance the tissue repair process in a diabetes model. Similar effects were achieved with laser therapy applied a single time with an energy density of 4 J/cm2 and applied four times with an energy density of 1 J/cm2. The application of laser therapy in the inflammatory phase was the most important factor to the enhancement of the tissue repair process.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/25909480

Antihyperglycaemic effect of laser acupuncture treatment at BL20 in diabetic rats.

Cornejo-Garrido J1, Becerril-Chávez F2, Carlín-Vargas G2, Ordoñez-Rodríguez JM2, Abrajan-González Mdel C2, de la Cruz-Ramírez R2, Ordaz-Pichardo C1. - Acupunct Med. 2014 Dec;32(6):486-94. doi: 10.1136/acupmed-2014-010573. Epub 2014 Sep 29. ()
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Background: To investigate the antihyperglycaemic activity of laser acupuncture stimulation at 650 and 980 nm at BL20 in streptozotocin (STZ)-induced diabetic rats.

Abstract: Erratum in Correction. [Acupunct Med. 2015]

Methods: Seventy healthy adult male albino Wistar rats weighing 250±50 g were divided into seven groups of 10 animals each. Groups I-III comprised healthy control rats which were untreated (I) or stimulated with laser acupuncture at 650 nm (II) and 980 nm (III), respectively. Groups IV-VII underwent induction of diabetes with a single intraperitoneal administration of STZ at 50 mg/kg. Animals with blood glucose levels of ≥200 mg/dL on the fifth day were used for the experiments and were left untreated (group IV), treated with glibenclamide (group V) or stimulated with laser acupuncture at 650 nm (group VI) and 980 nm (group VII), respectively. Laser acupuncture was applied at BL20 on alternate days for a total of 12 sessions over a 28-day period.

Results: After 28 days of treatment, STZ-induced diabetic rats stimulated with laser acupuncture at 650 and 980 nm had significantly lower glucose levels compared with untreated diabetic rats (242.0±65.0 and 129.8±33.2 vs 376.5±10.0 mg/dL, both p≤0.05). Treatment at 980 nm also attenuated the increase in glucose between day 1 and day 28 compared with the glibenclamide-treated diabetic group (41.5±19.6 mg/dL vs 164.1±13.7 g/dL, p<0.05). Laser acupuncture treatment did not affect the blood count or biochemical profile and was not associated with any morphological changes in the pancreas, liver, kidney or spleen.

Conclusions: Stimulation with laser acupuncture at 650 and 980 nm at BL20 in STZ-induced diabetic rats has antihyperglycaemic activity. The results support further evaluation of laser acupuncture as an alternative or complementary treatment for the control of hyperglycaemia.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/25267728

Defining a therapeutic window for laser irradiation (810 nm) applied to the inguinal region to ameliorate diabetes in diabetic mice.

Peplow PV1, Baxter GD. - Photomed Laser Surg. 2014 Sep;32(9):500-4. doi: 10.1089/pho.2014.3745. Epub 2014 Aug 7. ()
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Intro: The purpose of this study was to determine a therapeutic window of antidiabetic effect by laser irradiating the left inguinal region of diabetic mice (810 nm 20.4 and 40.8 J/cm(2)) for 7 days.

Background: The purpose of this study was to determine a therapeutic window of antidiabetic effect by laser irradiating the left inguinal region of diabetic mice (810 nm 20.4 and 40.8 J/cm(2)) for 7 days.

Abstract: Abstract OBJECTIVE: The purpose of this study was to determine a therapeutic window of antidiabetic effect by laser irradiating the left inguinal region of diabetic mice (810 nm 20.4 and 40.8 J/cm(2)) for 7 days. BACKGROUND DATA: Irradiation of 810 nm 10.2 J/cm(2) to the left inguinal region of diabetic mice for 7 days significantly decreased blood plasma fructosamine compared with nonirradiated controls. METHODS: Forty-seven diabetic mice were used. Body weight and water intake of the mice were measured daily for 7 days prior to start of treatment (day 0). Mice were irradiated on the left inguinal region with 810 nm laser 20.4 J/cm(2) (n=15) or 40.8 J/cm(2) (n=15) for 7 days, or were not irradiated (control, n=17). Body weight and water intake were measured to day 7. On day 7, mice were fasted for 5 h, anesthetized with sodium pentobarbitone (i.p.), and blood plasma was collected. The blood plasma was assayed for glucose and fructosamine. RESULTS: Water intake was significantly increased on day 7 compared with day 0 for diabetic mice receiving laser treatment. Blood plasma glucose levels on day 7 for diabetic mice irradiated 20.4 and 40.8 J/cm(2) were not significantly different than for nonirradiated controls. The blood plasma fructosamine level of diabetic mice irradiated with 20.4 J/cm(2) was significantly lower than for nonirradiated controls, whereas that for diabetic mice irradiated with 40.8 J/cm(2) was not significantly different than for nonirradiated controls. CONCLUSIONS: Irradiation (810 nm laser 10.2-20.4 J/cm(2)) to the left inguinal region of diabetic mice for 7 days has the potential to ameliorate diabetes, as is shown by decreased blood plasma fructosamine.

Methods: Irradiation of 810 nm 10.2 J/cm(2) to the left inguinal region of diabetic mice for 7 days significantly decreased blood plasma fructosamine compared with nonirradiated controls.

Results: Forty-seven diabetic mice were used. Body weight and water intake of the mice were measured daily for 7 days prior to start of treatment (day 0). Mice were irradiated on the left inguinal region with 810 nm laser 20.4 J/cm(2) (n=15) or 40.8 J/cm(2) (n=15) for 7 days, or were not irradiated (control, n=17). Body weight and water intake were measured to day 7. On day 7, mice were fasted for 5 h, anesthetized with sodium pentobarbitone (i.p.), and blood plasma was collected. The blood plasma was assayed for glucose and fructosamine.

Conclusions: Water intake was significantly increased on day 7 compared with day 0 for diabetic mice receiving laser treatment. Blood plasma glucose levels on day 7 for diabetic mice irradiated 20.4 and 40.8 J/cm(2) were not significantly different than for nonirradiated controls. The blood plasma fructosamine level of diabetic mice irradiated with 20.4 J/cm(2) was significantly lower than for nonirradiated controls, whereas that for diabetic mice irradiated with 40.8 J/cm(2) was not significantly different than for nonirradiated controls.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/25102241

Low-level light therapy induces mucosal healing in a murine model of dextran-sodium-sulfate induced colitis.

Zigmond E1, Varol C, Kaplan M, Shapira O, Melzer E. - Photomed Laser Surg. 2014 Aug;32(8):450-7. doi: 10.1089/pho.2013.3626. ()
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Intro: The aim of this study was to demonstrate the effect of low-level light therapy (LLLT) in an acute colitis model in mice.

Background: The aim of this study was to demonstrate the effect of low-level light therapy (LLLT) in an acute colitis model in mice.

Abstract: Abstract OBJECTIVE: The aim of this study was to demonstrate the effect of low-level light therapy (LLLT) in an acute colitis model in mice. BACKGROUND DATA: Low-level light therapy (LLLT) has been shown to be an effective treatment for various inflammatory processes such as oral mucositis and diabetic foot ulcers. METHODS: Colitis was induced by dextran sodium sulfate (DSS) in mice in four blinded controlled studies (validation of model, efficacy study, and two studies for evaluation of optimal dose). LLLT was applied to the colon utilizing a small diameter endoscope with an LED-based light source in several wavelengths (440, 660, and 850 nm at 1 J/cm(2)) and then 850 nm at several doses (1, 0.5, 0.25, and 0.1 J/cm(2)). LLLT was initiated 1 day prior to induction of colitis and went on for the 6 day induction period as well as for the following 3-10 days. Dose was controlled by changing exposure time. Disease activity was scored endoscopically and by histopathological assessment. RESULTS: Statistically significant improvement in disease severity was observed in the treatment groups compared with the control groups. The three wavelengths used demonstrated efficacy, and a clear dose-response curve was observed for one of the wavelengths (850 nm). On day 11, colonoscopic scoring in the sham-treated mice increased from 7.9±1.3 to 12.2±2.2, while activity in all treated groups remained stable. CONCLUSIONS: Photobiostimulation with LLLT has a significant positive effect on disease progression in mice with DSS colitis.

Methods: Low-level light therapy (LLLT) has been shown to be an effective treatment for various inflammatory processes such as oral mucositis and diabetic foot ulcers.

Results: Colitis was induced by dextran sodium sulfate (DSS) in mice in four blinded controlled studies (validation of model, efficacy study, and two studies for evaluation of optimal dose). LLLT was applied to the colon utilizing a small diameter endoscope with an LED-based light source in several wavelengths (440, 660, and 850 nm at 1 J/cm(2)) and then 850 nm at several doses (1, 0.5, 0.25, and 0.1 J/cm(2)). LLLT was initiated 1 day prior to induction of colitis and went on for the 6 day induction period as well as for the following 3-10 days. Dose was controlled by changing exposure time. Disease activity was scored endoscopically and by histopathological assessment.

Conclusions: Statistically significant improvement in disease severity was observed in the treatment groups compared with the control groups. The three wavelengths used demonstrated efficacy, and a clear dose-response curve was observed for one of the wavelengths (850 nm). On day 11, colonoscopic scoring in the sham-treated mice increased from 7.9±1.3 to 12.2±2.2, while activity in all treated groups remained stable.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/25101535

Safety of transfoveal subthreshold diode micropulse laser for fovea-involving diabetic macular edema in eyes with good visual acuity.

Luttrull JK1, Sinclair SH. - Retina. 2014 Oct;34(10):2010-20. doi: 10.1097/IAE.0000000000000177. ()
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Intro: To determine the safety of transfoveal subthreshold diode micropulse laser for fovea-involving diabetic macular edema.

Background: To determine the safety of transfoveal subthreshold diode micropulse laser for fovea-involving diabetic macular edema.

Abstract: Abstract PURPOSE: To determine the safety of transfoveal subthreshold diode micropulse laser for fovea-involving diabetic macular edema. METHODS: The records of all patients treated with transfoveal subthreshold diode micropulse laser for fovea-involving diabetic macular edema in two retina clinics were reviewed. The eligibility included fovea-involving diabetic macular edema by spectral domain optical coherence tomography and pretreatment visual acuity of 20/40 or better. RESULTS: Thirty-nine eyes of 27 patients aged 50 years to 87 years (mean, 69 years) were included. Postoperative follow-up ranged from 3 months to 36 months (mean, 11 months). Fourteen patients were insulin dependent, and 19 had nonproliferative retinopathy. The preoperative visual acuity was 20/20 (10 eyes), 20/25 (10 eyes), 20/30 (8 eyes), and 20/40 (11 eyes). No eye had evidence of laser-induced macular damage by any imaging means postoperatively. There were no adverse treatment effects. Logarithm of the minimum angle of resolution visual acuity was improved on average of 0.03 units at 4 months to 7 months of follow-up (P = 0.0449, paired t-test) and otherwise stable. The central foveal thickness was improved at 4 months to 7 months (P = 0.05, paired t-test) and 8 months to 12 months, postoperatively (P = 0.04, mixed model accounting). Maximum macular thickness was improved at 4 months to 7 months postoperatively (P = 0.01, paired t-test and mixed model accounting). CONCLUSION: In a small retrospective series, transfoveal subthreshold diode micropulse laser was safe and effective for the treatment of fovea-involving diabetic macular edema in eyes with good preoperative visual acuity that were not the candidates for conventional photocoagulation or intravitreal injection. Further study is warranted.

Methods: The records of all patients treated with transfoveal subthreshold diode micropulse laser for fovea-involving diabetic macular edema in two retina clinics were reviewed. The eligibility included fovea-involving diabetic macular edema by spectral domain optical coherence tomography and pretreatment visual acuity of 20/40 or better.

Results: Thirty-nine eyes of 27 patients aged 50 years to 87 years (mean, 69 years) were included. Postoperative follow-up ranged from 3 months to 36 months (mean, 11 months). Fourteen patients were insulin dependent, and 19 had nonproliferative retinopathy. The preoperative visual acuity was 20/20 (10 eyes), 20/25 (10 eyes), 20/30 (8 eyes), and 20/40 (11 eyes). No eye had evidence of laser-induced macular damage by any imaging means postoperatively. There were no adverse treatment effects. Logarithm of the minimum angle of resolution visual acuity was improved on average of 0.03 units at 4 months to 7 months of follow-up (P = 0.0449, paired t-test) and otherwise stable. The central foveal thickness was improved at 4 months to 7 months (P = 0.05, paired t-test) and 8 months to 12 months, postoperatively (P = 0.04, mixed model accounting). Maximum macular thickness was improved at 4 months to 7 months postoperatively (P = 0.01, paired t-test and mixed model accounting).

Conclusions: In a small retrospective series, transfoveal subthreshold diode micropulse laser was safe and effective for the treatment of fovea-involving diabetic macular edema in eyes with good preoperative visual acuity that were not the candidates for conventional photocoagulation or intravitreal injection. Further study is warranted.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24837050

In vitro Therapeutic Effects of Low Level Laser at mRNA Level on the Release of Skin Growth Factors from Fibroblasts in Diabetic Mice.

Khoo NK1, Shokrgozar MA2, Kashani IR3, Amanzadeh A2, Mostafavi E4, Sanati H2, Habibi L1, Talebi S1, Abouzaripour M3, Akrami SM1. - Avicenna J Med Biotechnol. 2014 Apr;6(2):113-8. ()
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Intro: Numerous in vitro reports suggest that Low Level Laser Therapy (LLLT) affects cellular processes by biostimulation, however most of them emphasize on using visible light lasers which have low penetration. The aim of this study was to determine the effect of infrared laser light (which is more useful in clinic because of its higher penetration) on secretion of Fibroblast Growth Factor (FGF), Platelet Derived Growth Factor (PDGF) and Vascular Endothelial Growth Factor (VEGF), as important growth factors in wound healing.

Background: Numerous in vitro reports suggest that Low Level Laser Therapy (LLLT) affects cellular processes by biostimulation, however most of them emphasize on using visible light lasers which have low penetration. The aim of this study was to determine the effect of infrared laser light (which is more useful in clinic because of its higher penetration) on secretion of Fibroblast Growth Factor (FGF), Platelet Derived Growth Factor (PDGF) and Vascular Endothelial Growth Factor (VEGF), as important growth factors in wound healing.

Abstract: Abstract BACKGROUND: Numerous in vitro reports suggest that Low Level Laser Therapy (LLLT) affects cellular processes by biostimulation, however most of them emphasize on using visible light lasers which have low penetration. The aim of this study was to determine the effect of infrared laser light (which is more useful in clinic because of its higher penetration) on secretion of Fibroblast Growth Factor (FGF), Platelet Derived Growth Factor (PDGF) and Vascular Endothelial Growth Factor (VEGF), as important growth factors in wound healing. METHODS: Fibroblasts were extracted from the skin of 7 diabetic and 7 nondiabetic mice and cultured. Cell cultures of experimental group were irradiated with single dose of LLLT (energy density of 1 J/cm (2)) using an 810 nm continuous wave laser and the control group was not irradiated. Secretion of growth factors by skin fibroblasts were quantified through real time poly-merase chain reaction. RESULTS: Diabetic irradiated group showed significant increase in FGF (p = 0.017) expression, although PDGF increased and VEGF decreased in both diabetic and nondiabetic irradiated groups, but these variations were not statistically significant. CONCLUSION: These results suggest that LLLT may play an important role in wound healing by stimulating the fibroblasts.

Methods: Fibroblasts were extracted from the skin of 7 diabetic and 7 nondiabetic mice and cultured. Cell cultures of experimental group were irradiated with single dose of LLLT (energy density of 1 J/cm (2)) using an 810 nm continuous wave laser and the control group was not irradiated. Secretion of growth factors by skin fibroblasts were quantified through real time poly-merase chain reaction.

Results: Diabetic irradiated group showed significant increase in FGF (p = 0.017) expression, although PDGF increased and VEGF decreased in both diabetic and nondiabetic irradiated groups, but these variations were not statistically significant.

Conclusions: These results suggest that LLLT may play an important role in wound healing by stimulating the fibroblasts.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24834313

Histological analysis of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low-level laser therapy.

Maia LG1, Alves AV2, Bastos TS3, Moromizato LS4, Lima-Verde IB5, Ribeiro MA6, Gandini Júnior LG7, de Albuquerque-Júnior RL8. - J Photochem Photobiol B. 2014 Jun 5;135:65-74. doi: 10.1016/j.jphotobiol.2014.03.023. Epub 2014 Apr 12. ()
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Intro: The purpose of this research was to evaluate the histological changes of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low level laser therapy (LLLT).

Background: The purpose of this research was to evaluate the histological changes of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low level laser therapy (LLLT).

Abstract: Abstract OBJECTIVE: The purpose of this research was to evaluate the histological changes of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low level laser therapy (LLLT). METHODS: The movement of the upper molar was performed in 60 male Wistar rats divided into four groups (n=15): CTR (control), DBT (diabetic), CTR/LT (irradiated control) and DBT/LT (irradiated diabetic). Diabetes was induced with alloxan (150 mg/kg, i.p.). LLLT was applied with GaAlAs laser at 780 nm (35 J/cm(2)). After 7, 13 and 19 days, the periodontal ligament and alveolar bone were histologically analyzed. RESULTS: The mean of osteoblasts (p<0.01) and blood vessels (p<0.05) were significantly decreased in DBT compared with CTR at 7 days, whereas the mean of osteoclasts was lower at 7 (p<0.001) and 13 days (p<0.05). In DBT/LT, only the mean of osteoclasts was lower than in CTR (p<0.05) at 7 days, but no difference was observed at 13 and 19 days (p>0.05). The collagenization of the periodontal ligament was impaired in DBT, whereas DBT/LLT showed density/disposition of the collagen fibers similar to those observed in CTR. CONCLUSIONS: LLLT improved the periodontal ligament and alveolar bone remodeling activity in diabetic rats during dental movement. Copyright © 2014 Elsevier B.V. All rights reserved.

Methods: The movement of the upper molar was performed in 60 male Wistar rats divided into four groups (n=15): CTR (control), DBT (diabetic), CTR/LT (irradiated control) and DBT/LT (irradiated diabetic). Diabetes was induced with alloxan (150 mg/kg, i.p.). LLLT was applied with GaAlAs laser at 780 nm (35 J/cm(2)). After 7, 13 and 19 days, the periodontal ligament and alveolar bone were histologically analyzed.

Results: The mean of osteoblasts (p<0.01) and blood vessels (p<0.05) were significantly decreased in DBT compared with CTR at 7 days, whereas the mean of osteoclasts was lower at 7 (p<0.001) and 13 days (p<0.05). In DBT/LT, only the mean of osteoclasts was lower than in CTR (p<0.05) at 7 days, but no difference was observed at 13 and 19 days (p>0.05). The collagenization of the periodontal ligament was impaired in DBT, whereas DBT/LLT showed density/disposition of the collagen fibers similar to those observed in CTR.

Conclusions: LLLT improved the periodontal ligament and alveolar bone remodeling activity in diabetic rats during dental movement.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24814932

Low level laser therapy for the treatment of diabetic foot ulcers: a critical survey.

Beckmann KH1, Meyer-Hamme G1, Schröder S1. - Evid Based Complement Alternat Med. 2014;2014:626127. doi: 10.1155/2014/626127. Epub 2014 Mar 16. ()
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Intro: Diabetic foot ulcers as one of the most common complications of diabetes mellitus are defined as nonhealing or long-lasting chronic skin ulcers in diabetic patients. Multidisciplinary care for the diabetic foot is common, but treatment results are often unsatisfactory. Low level laser therapy (LLLT) on wound areas as well as on acupuncture points, as a noninvasive, pain-free method with minor side effects, has been considered as a possible treatment option for the diabetic foot syndrome. A systematic literature review identified 1764 articles on this topic. Finally, we adopted 22 eligible references; 8 of them were cell studies, 6 were animal studies, and 8 were clinical trials. Cell studies and animal studies gave evidence of cellular migration, viability, and proliferation of fibroblast cells, quicker reepithelization and reformed connective tissue, enhancement of microcirculation, and anti-inflammatory effects by inhibition of prostaglandine, interleukin, and cytokine as well as direct antibacterial effects by induction of reactive oxygen species (ROS). The transferral of these data into clinical medicine is under debate. The majority of clinical studies show a potential benefit of LLLT in wound healing of diabetic ulcers. But there are a lot of aspects in these studies limiting final evidence about the actual output of this kind of treatment method. In summary, all studies give enough evidence to continue research on laser therapy for diabetic ulcers, but clinical trials using human models do not provide sufficient evidence to establish the usefulness of LLLT as an effective tool in wound care regimes at present. Further well designed research trials are required to determine the true value of LLLT in routine wound care.

Background: Diabetic foot ulcers as one of the most common complications of diabetes mellitus are defined as nonhealing or long-lasting chronic skin ulcers in diabetic patients. Multidisciplinary care for the diabetic foot is common, but treatment results are often unsatisfactory. Low level laser therapy (LLLT) on wound areas as well as on acupuncture points, as a noninvasive, pain-free method with minor side effects, has been considered as a possible treatment option for the diabetic foot syndrome. A systematic literature review identified 1764 articles on this topic. Finally, we adopted 22 eligible references; 8 of them were cell studies, 6 were animal studies, and 8 were clinical trials. Cell studies and animal studies gave evidence of cellular migration, viability, and proliferation of fibroblast cells, quicker reepithelization and reformed connective tissue, enhancement of microcirculation, and anti-inflammatory effects by inhibition of prostaglandine, interleukin, and cytokine as well as direct antibacterial effects by induction of reactive oxygen species (ROS). The transferral of these data into clinical medicine is under debate. The majority of clinical studies show a potential benefit of LLLT in wound healing of diabetic ulcers. But there are a lot of aspects in these studies limiting final evidence about the actual output of this kind of treatment method. In summary, all studies give enough evidence to continue research on laser therapy for diabetic ulcers, but clinical trials using human models do not provide sufficient evidence to establish the usefulness of LLLT as an effective tool in wound care regimes at present. Further well designed research trials are required to determine the true value of LLLT in routine wound care.

Abstract: Abstract Diabetic foot ulcers as one of the most common complications of diabetes mellitus are defined as nonhealing or long-lasting chronic skin ulcers in diabetic patients. Multidisciplinary care for the diabetic foot is common, but treatment results are often unsatisfactory. Low level laser therapy (LLLT) on wound areas as well as on acupuncture points, as a noninvasive, pain-free method with minor side effects, has been considered as a possible treatment option for the diabetic foot syndrome. A systematic literature review identified 1764 articles on this topic. Finally, we adopted 22 eligible references; 8 of them were cell studies, 6 were animal studies, and 8 were clinical trials. Cell studies and animal studies gave evidence of cellular migration, viability, and proliferation of fibroblast cells, quicker reepithelization and reformed connective tissue, enhancement of microcirculation, and anti-inflammatory effects by inhibition of prostaglandine, interleukin, and cytokine as well as direct antibacterial effects by induction of reactive oxygen species (ROS). The transferral of these data into clinical medicine is under debate. The majority of clinical studies show a potential benefit of LLLT in wound healing of diabetic ulcers. But there are a lot of aspects in these studies limiting final evidence about the actual output of this kind of treatment method. In summary, all studies give enough evidence to continue research on laser therapy for diabetic ulcers, but clinical trials using human models do not provide sufficient evidence to establish the usefulness of LLLT as an effective tool in wound care regimes at present. Further well designed research trials are required to determine the true value of LLLT in routine wound care.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24744814

Low-level laser therapy with 810 nm wavelength improves skin wound healing in rats with streptozotocin-induced diabetes.

Dancáková L1, Vasilenko T, Ková� I, Jakub�ová K, Hollý M, Revajová V, Sabol F, Tomori Z, Iversen M, Gál P, Bjordal JM. - Photomed Laser Surg. 2014 Apr;32(4):198-204. doi: 10.1089/pho.2013.3586. Epub 2014 Mar 24. ()
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Intro: The aim of present study was to evaluate whether low-level laser therapy (LLLT) can reverse the impaired wound healing process in diabetic rats.

Background: The aim of present study was to evaluate whether low-level laser therapy (LLLT) can reverse the impaired wound healing process in diabetic rats.

Abstract: Abstract OBJECTIVE: The aim of present study was to evaluate whether low-level laser therapy (LLLT) can reverse the impaired wound healing process in diabetic rats. BACKGROUND DATA: Impaired wound healing in diabetic patients represents a major health problem. Recent studies have indicated that LLLT may improve wound healing in diabetic rats, but the optimal treatment parameters are still unknown. MATERIALS AND METHODS: Male Sprague-Dawley rats (n=21) were randomly divided into three groups: a healthy control group, a diabetic sham-treated group, and a diabetic LLLT-treated group. Diabetes mellitus was then induced by streptozotocin administration to the two diabetic groups. One 4 cm long full thickness skin incision and one full thickness circular excision (diameter=4 mm) were performed on the back of each rat. An infrared 810 nm laser with an output of 30 mW, a power density of 30 mW/cm(2), and a spot size of 1 cm(2) was used to irradiate each wound for 30 sec (daily dose of 0.9 J/cm(2)/wound/day). RESULTS: In diabetic rats, the histology of LLLT-treated excisions revealed a similar healing response to that in nondiabetic controls, with significantly more mature granulation tissue than in the sham-treated diabetic control group. LLLT reduced the loss of tensile strength, and increased the incision wound stiffness significantly compared with sham-irradiated rats, but this did not achieve the same level as in the nondiabetic controls. CONCLUSIONS: Our study demonstrates that infrared LLLT can improve wound healing in diabetic rats. Nevertheless, further research needs to be performed to evaluate the exact underlying mechanism and to further optimize LLLT parameters for clinical use.

Methods: Impaired wound healing in diabetic patients represents a major health problem. Recent studies have indicated that LLLT may improve wound healing in diabetic rats, but the optimal treatment parameters are still unknown.

Results: Male Sprague-Dawley rats (n=21) were randomly divided into three groups: a healthy control group, a diabetic sham-treated group, and a diabetic LLLT-treated group. Diabetes mellitus was then induced by streptozotocin administration to the two diabetic groups. One 4 cm long full thickness skin incision and one full thickness circular excision (diameter=4 mm) were performed on the back of each rat. An infrared 810 nm laser with an output of 30 mW, a power density of 30 mW/cm(2), and a spot size of 1 cm(2) was used to irradiate each wound for 30 sec (daily dose of 0.9 J/cm(2)/wound/day).

Conclusions: In diabetic rats, the histology of LLLT-treated excisions revealed a similar healing response to that in nondiabetic controls, with significantly more mature granulation tissue than in the sham-treated diabetic control group. LLLT reduced the loss of tensile strength, and increased the incision wound stiffness significantly compared with sham-irradiated rats, but this did not achieve the same level as in the nondiabetic controls.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24661084

Evaluating the effect of low-level laser therapy on healing of tentomized Achilles tendon in streptozotocin-induced diabetic rats by light microscopical and gene expression examinations.

Aliodoust M1, Bayat M, Jalili MR, Sharifian Z, Dadpay M, Akbari M, Bayat M, Khoshvaghti A, Bayat H. - Lasers Med Sci. 2014 Jul;29(4):1495-503. doi: 10.1007/s10103-014-1561-0. Epub 2014 Mar 13. ()
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Intro: Tendon healing is impaired in individuals diagnosed with diabetes mellitus (DM). According to research, there is considerable improvement in the healing of surgically tenotomized Achilles tendons following low-level laser therapy (LLLT) in non-diabetic, healthy animals. This study uses light microscopic (LM) and semi-quantitative reverse transcription PCR (RT-PCR) analyses to evaluate the ability of LLLT in healing Achilles tendons from streptozotocin-induced diabetic (STZ-D) rats. A total of 88 rats were randomly divided into two groups, non-diabetic and diabetic. DM was induced in the rats by injections of STZ. The right Achilles tendons of all rats were tenotomized 1 month after administration of STZ. Laser-treated rats were treated with a helium-neon (He-Ne) laser that had a 632.8-nm wavelength and 7.2-mW average power. Experimental group rats received a daily dose of 0.014 J (energy density, 2.9 J/cm(2)). Control rats did not receive LLLT. Animals were sacrificed on days 5, 10, and 15 post-operatively for semi-quantitative LM and semi-quantitative RT-PCR examinations of transforming growth factor-beta1 (TGF-β1) gene expression. The chi-square test showed that LLLT significantly reduced inflammation in non-diabetic rats compared with their non-diabetic controls (p = 0.02). LLLT significantly decreased inflammation in diabetic rats on days 5 (p = 0.03) and 10 (p = 0.02) compared to the corresponding control diabetic rats. According to the student's t test, LLLT significantly increased TGF-β1 gene expression in healthy (p = 0.000) and diabetic (p = 0.000) rats compared to their relevant controls. The He-Ne laser was effective in altering the inflammatory reaction and increasing TGF-β1 gene production.

Background: Tendon healing is impaired in individuals diagnosed with diabetes mellitus (DM). According to research, there is considerable improvement in the healing of surgically tenotomized Achilles tendons following low-level laser therapy (LLLT) in non-diabetic, healthy animals. This study uses light microscopic (LM) and semi-quantitative reverse transcription PCR (RT-PCR) analyses to evaluate the ability of LLLT in healing Achilles tendons from streptozotocin-induced diabetic (STZ-D) rats. A total of 88 rats were randomly divided into two groups, non-diabetic and diabetic. DM was induced in the rats by injections of STZ. The right Achilles tendons of all rats were tenotomized 1 month after administration of STZ. Laser-treated rats were treated with a helium-neon (He-Ne) laser that had a 632.8-nm wavelength and 7.2-mW average power. Experimental group rats received a daily dose of 0.014 J (energy density, 2.9 J/cm(2)). Control rats did not receive LLLT. Animals were sacrificed on days 5, 10, and 15 post-operatively for semi-quantitative LM and semi-quantitative RT-PCR examinations of transforming growth factor-beta1 (TGF-β1) gene expression. The chi-square test showed that LLLT significantly reduced inflammation in non-diabetic rats compared with their non-diabetic controls (p = 0.02). LLLT significantly decreased inflammation in diabetic rats on days 5 (p = 0.03) and 10 (p = 0.02) compared to the corresponding control diabetic rats. According to the student's t test, LLLT significantly increased TGF-β1 gene expression in healthy (p = 0.000) and diabetic (p = 0.000) rats compared to their relevant controls. The He-Ne laser was effective in altering the inflammatory reaction and increasing TGF-β1 gene production.

Abstract: Abstract Tendon healing is impaired in individuals diagnosed with diabetes mellitus (DM). According to research, there is considerable improvement in the healing of surgically tenotomized Achilles tendons following low-level laser therapy (LLLT) in non-diabetic, healthy animals. This study uses light microscopic (LM) and semi-quantitative reverse transcription PCR (RT-PCR) analyses to evaluate the ability of LLLT in healing Achilles tendons from streptozotocin-induced diabetic (STZ-D) rats. A total of 88 rats were randomly divided into two groups, non-diabetic and diabetic. DM was induced in the rats by injections of STZ. The right Achilles tendons of all rats were tenotomized 1 month after administration of STZ. Laser-treated rats were treated with a helium-neon (He-Ne) laser that had a 632.8-nm wavelength and 7.2-mW average power. Experimental group rats received a daily dose of 0.014 J (energy density, 2.9 J/cm(2)). Control rats did not receive LLLT. Animals were sacrificed on days 5, 10, and 15 post-operatively for semi-quantitative LM and semi-quantitative RT-PCR examinations of transforming growth factor-beta1 (TGF-β1) gene expression. The chi-square test showed that LLLT significantly reduced inflammation in non-diabetic rats compared with their non-diabetic controls (p = 0.02). LLLT significantly decreased inflammation in diabetic rats on days 5 (p = 0.03) and 10 (p = 0.02) compared to the corresponding control diabetic rats. According to the student's t test, LLLT significantly increased TGF-β1 gene expression in healthy (p = 0.000) and diabetic (p = 0.000) rats compared to their relevant controls. The He-Ne laser was effective in altering the inflammatory reaction and increasing TGF-β1 gene production.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24622817

Effect of equal daily doses achieved by different power densities of low-level laser therapy at 635 nm on open skin wound healing in normal and diabetic rats.

Kilík R1, Lakyová L1, Sabo J2, Kruzliak P3, Lacjaková K4, Vasilenko T5, Vidová M1, Longauer F6, Radoňak J1. - Biomed Res Int. 2014;2014:269253. doi: 10.1155/2014/269253. Epub 2014 Jan 16. ()
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Intro: Despite the fact that the molecular mechanism of low-level laser therapy (LLLT) is not yet known, the exploitation of phototherapy in clinical medicine and surgery is of great interest. The present study investigates the effects of LLLT on open skin wound healing in normal and diabetic rats.

Background: Despite the fact that the molecular mechanism of low-level laser therapy (LLLT) is not yet known, the exploitation of phototherapy in clinical medicine and surgery is of great interest. The present study investigates the effects of LLLT on open skin wound healing in normal and diabetic rats.

Abstract: Abstract BACKGROUND AND OBJECTIVE: Despite the fact that the molecular mechanism of low-level laser therapy (LLLT) is not yet known, the exploitation of phototherapy in clinical medicine and surgery is of great interest. The present study investigates the effects of LLLT on open skin wound healing in normal and diabetic rats. MATERIALS AND METHODS: Four round full-thickness skin wounds on dorsum were performed in male adult nondiabetic (n = 24) and diabetic (n = 24) Sprague-Dawley rats. AlGaInP (635 nm, wavelength; 5 J/cm(2), daily dose) was used to deliver power densities of 1, 5, and 15 mW/cm(2) three times daily until euthanasia. RESULTS: PMNL infiltration was lower in the irradiated groups (15 mW/cm(2)). The synthesis and organisation of collagen fibres were consecutively enhanced in the 5 mW/cm(2) and 15 mW/cm(2) groups compared to the others in nondiabetic rats. In the diabetic group the only significant difference was recorded in the ratio PMNL/Ma at 15 mW/cm(2). A significant difference in the number of newly formed capillaries in the irradiated group (5, 15 mW/cm(2)) was recorded on day six after injury compared to the control group. CONCLUSION: LLLT confers a protective effect against excessive inflammatory tissue response; it stimulates neovascularization and the early formation of collagen fibres.

Methods: Four round full-thickness skin wounds on dorsum were performed in male adult nondiabetic (n = 24) and diabetic (n = 24) Sprague-Dawley rats. AlGaInP (635 nm, wavelength; 5 J/cm(2), daily dose) was used to deliver power densities of 1, 5, and 15 mW/cm(2) three times daily until euthanasia.

Results: PMNL infiltration was lower in the irradiated groups (15 mW/cm(2)). The synthesis and organisation of collagen fibres were consecutively enhanced in the 5 mW/cm(2) and 15 mW/cm(2) groups compared to the others in nondiabetic rats. In the diabetic group the only significant difference was recorded in the ratio PMNL/Ma at 15 mW/cm(2). A significant difference in the number of newly formed capillaries in the irradiated group (5, 15 mW/cm(2)) was recorded on day six after injury compared to the control group.

Conclusions: LLLT confers a protective effect against excessive inflammatory tissue response; it stimulates neovascularization and the early formation of collagen fibres.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24551842

Shedding light on a new treatment for diabetic wound healing: a review on phototherapy.

Houreld NN1. - ScientificWorldJournal. 2014 Jan 6;2014:398412. doi: 10.1155/2014/398412. eCollection 2014. ()
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Intro: Impaired wound healing is a common complication associated with diabetes with complex pathophysiological underlying mechanisms and often necessitates amputation. With the advancement in laser technology, irradiation of these wounds with low-intensity laser irradiation (LILI) or phototherapy, has shown a vast improvement in wound healing. At the correct laser parameters, LILI has shown to increase migration, viability, and proliferation of diabetic cells in vitro; there is a stimulatory effect on the mitochondria with a resulting increase in adenosine triphosphate (ATP). In addition, LILI also has an anti-inflammatory and protective effect on these cells. In light of the ever present threat of diabetic foot ulcers, infection, and amputation, new improved therapies and the fortification of wound healing research deserves better prioritization. In this review we look at the complications associated with diabetic wound healing and the effect of laser irradiation both in vitro and in vivo in diabetic wound healing.

Background: Impaired wound healing is a common complication associated with diabetes with complex pathophysiological underlying mechanisms and often necessitates amputation. With the advancement in laser technology, irradiation of these wounds with low-intensity laser irradiation (LILI) or phototherapy, has shown a vast improvement in wound healing. At the correct laser parameters, LILI has shown to increase migration, viability, and proliferation of diabetic cells in vitro; there is a stimulatory effect on the mitochondria with a resulting increase in adenosine triphosphate (ATP). In addition, LILI also has an anti-inflammatory and protective effect on these cells. In light of the ever present threat of diabetic foot ulcers, infection, and amputation, new improved therapies and the fortification of wound healing research deserves better prioritization. In this review we look at the complications associated with diabetic wound healing and the effect of laser irradiation both in vitro and in vivo in diabetic wound healing.

Abstract: Abstract Impaired wound healing is a common complication associated with diabetes with complex pathophysiological underlying mechanisms and often necessitates amputation. With the advancement in laser technology, irradiation of these wounds with low-intensity laser irradiation (LILI) or phototherapy, has shown a vast improvement in wound healing. At the correct laser parameters, LILI has shown to increase migration, viability, and proliferation of diabetic cells in vitro; there is a stimulatory effect on the mitochondria with a resulting increase in adenosine triphosphate (ATP). In addition, LILI also has an anti-inflammatory and protective effect on these cells. In light of the ever present threat of diabetic foot ulcers, infection, and amputation, new improved therapies and the fortification of wound healing research deserves better prioritization. In this review we look at the complications associated with diabetic wound healing and the effect of laser irradiation both in vitro and in vivo in diabetic wound healing.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24511283

Histological and gene expression analysis of the effects of pulsed low-level laser therapy on wound healing of streptozotocin-induced diabetic rats.

Sharifian Z1, Bayat M, Alidoust M, Farahani RM, Bayat M, Rezaie F, Bayat H. - Lasers Med Sci. 2014 May;29(3):1227-35. doi: 10.1007/s10103-013-1500-5. Epub 2013 Dec 21. ()
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Intro: Diabetes mellitus (DM) is associated with poor wound healing. Studies have shown accelerated wound healing following pulsed low-level laser therapy (LLLT) in non-diabetic animals. The present study aims to evaluate the effect of pulsed LLLT on wound healing in streptozotocin-induced diabetic (STZ-D) rats. We divided 48 rats into two groups of non-diabetic and diabetic. Type 1 DM was induced in the diabetic rat group by injections of STZ. Two, full-thickness skin incisions were made on the dorsal region of each rat. One month after the STZ injection, wounds of the non-diabetic and diabetic rats were submitted to a pulsed, infrared 890-nm laser with an 80-Hz frequency and 0.2 J/cm(2) for each wound point. Control wounds did not receive LLLT. Animals were sacrificed on days 4, 7, and 15 post-injury for histomorphometry and reverse transcription polymerase chain reaction (RT-PCR) analyses of basic fibroblast growth factor (bFGF) gene expression. Pulsed LLLT significantly increased the numbers of macrophages, fibroblasts, and blood vessel sections compared to the corresponding control groups. Semi-quantitative analysis of bFGF gene expression at 48 h post-injury revealed a significant increase in gene expression in both non-diabetic and diabetic rats following LLLT (the ANOVA test). Pulsed LLLT at 0.2 J/cm(2) accelerated the wound healing process in both non-diabetic and diabetic rats as measured by histological characteristics and semi-quantitative bFGF gene expression.

Background: Diabetes mellitus (DM) is associated with poor wound healing. Studies have shown accelerated wound healing following pulsed low-level laser therapy (LLLT) in non-diabetic animals. The present study aims to evaluate the effect of pulsed LLLT on wound healing in streptozotocin-induced diabetic (STZ-D) rats. We divided 48 rats into two groups of non-diabetic and diabetic. Type 1 DM was induced in the diabetic rat group by injections of STZ. Two, full-thickness skin incisions were made on the dorsal region of each rat. One month after the STZ injection, wounds of the non-diabetic and diabetic rats were submitted to a pulsed, infrared 890-nm laser with an 80-Hz frequency and 0.2 J/cm(2) for each wound point. Control wounds did not receive LLLT. Animals were sacrificed on days 4, 7, and 15 post-injury for histomorphometry and reverse transcription polymerase chain reaction (RT-PCR) analyses of basic fibroblast growth factor (bFGF) gene expression. Pulsed LLLT significantly increased the numbers of macrophages, fibroblasts, and blood vessel sections compared to the corresponding control groups. Semi-quantitative analysis of bFGF gene expression at 48 h post-injury revealed a significant increase in gene expression in both non-diabetic and diabetic rats following LLLT (the ANOVA test). Pulsed LLLT at 0.2 J/cm(2) accelerated the wound healing process in both non-diabetic and diabetic rats as measured by histological characteristics and semi-quantitative bFGF gene expression.

Abstract: Abstract Diabetes mellitus (DM) is associated with poor wound healing. Studies have shown accelerated wound healing following pulsed low-level laser therapy (LLLT) in non-diabetic animals. The present study aims to evaluate the effect of pulsed LLLT on wound healing in streptozotocin-induced diabetic (STZ-D) rats. We divided 48 rats into two groups of non-diabetic and diabetic. Type 1 DM was induced in the diabetic rat group by injections of STZ. Two, full-thickness skin incisions were made on the dorsal region of each rat. One month after the STZ injection, wounds of the non-diabetic and diabetic rats were submitted to a pulsed, infrared 890-nm laser with an 80-Hz frequency and 0.2 J/cm(2) for each wound point. Control wounds did not receive LLLT. Animals were sacrificed on days 4, 7, and 15 post-injury for histomorphometry and reverse transcription polymerase chain reaction (RT-PCR) analyses of basic fibroblast growth factor (bFGF) gene expression. Pulsed LLLT significantly increased the numbers of macrophages, fibroblasts, and blood vessel sections compared to the corresponding control groups. Semi-quantitative analysis of bFGF gene expression at 48 h post-injury revealed a significant increase in gene expression in both non-diabetic and diabetic rats following LLLT (the ANOVA test). Pulsed LLLT at 0.2 J/cm(2) accelerated the wound healing process in both non-diabetic and diabetic rats as measured by histological characteristics and semi-quantitative bFGF gene expression.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24362922

Efficacy of low level laser therapy on wound healing in patients with chronic diabetic foot ulcers-a randomised control trial.

Kajagar BM1, Godhi AS, Pandit A, Khatri S. - Indian J Surg. 2012 Oct;74(5):359-63. doi: 10.1007/s12262-011-0393-4. Epub 2012 Apr 11. ()
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Intro: Foot ulcers are serious complications of Diabetes Mellitus (DM) and are known to be resistant to conventional treatment. They may herald severe complications if not treated wisely. Electromagnetic radiations in the form of photons are delivered to the ulcers in laser form to stimulate healing. This study was conducted to evaluate the efficacy of Low Level Laser Therapy (LLLT) in diabetic ulcer healing dynamics. To determine mean percentage reduction of wound area in study and control groups.

Background: Foot ulcers are serious complications of Diabetes Mellitus (DM) and are known to be resistant to conventional treatment. They may herald severe complications if not treated wisely. Electromagnetic radiations in the form of photons are delivered to the ulcers in laser form to stimulate healing. This study was conducted to evaluate the efficacy of Low Level Laser Therapy (LLLT) in diabetic ulcer healing dynamics. To determine mean percentage reduction of wound area in study and control groups.

Abstract: Abstract Foot ulcers are serious complications of Diabetes Mellitus (DM) and are known to be resistant to conventional treatment. They may herald severe complications if not treated wisely. Electromagnetic radiations in the form of photons are delivered to the ulcers in laser form to stimulate healing. This study was conducted to evaluate the efficacy of Low Level Laser Therapy (LLLT) in diabetic ulcer healing dynamics. To determine mean percentage reduction of wound area in study and control groups. SETTINGS: KLES Dr. Prabhakar Kore Hospital and Medical Research Centre, Belgaum. STUDY DESIGN: Randomized-Control Study. METHODS: A total of 68 patients with Type 2 DM having Meggitt-Wagner Grade I foot ulcers of atleast more than 4 weeks duration, less than 6 × 6 cm(2) with negative culture were studied. Patients were randomized into two groups of 34 each. Patients in study group received LLLT with conventional therapy and those in control group were treated with conventional therapy alone. Healing or percentage reduction in ulcer area over a period of 15 days after commencement of treatment was recorded. STATISTICAL ANALYSIS: Unpaired Student T Test and Mann Whitney U test. Mean age of the patients was 50.94 years in control group and 54.35 years in study group (p = 0.065). There was no significant difference between control and study group with respect to mean FBS and HbA1c levels (p > 0.05), suggesting no biochemical differences between two groups. Initial ulcer area was 2608.03 mm(2) in study group and 2747.17 mm(2) in control group (p = 0.361). Final ulcer area was 1564.79 mm(2) in study group and 2424.75 mm(2) in control group (p = 0.361). Percentage ulcer area reduction was 40.24 ± 6.30 mm(2) in study group and 11.87 ± 4.28 mm(2) in control group (p < 0.001, Z = 7.08). Low Level Laser Therapy is beneficial as an adjunct to conventional therapy in the treatment of diabetic foot ulcers (DFU).

Methods: KLES Dr. Prabhakar Kore Hospital and Medical Research Centre, Belgaum.

Results: Randomized-Control Study.

Conclusions: A total of 68 patients with Type 2 DM having Meggitt-Wagner Grade I foot ulcers of atleast more than 4 weeks duration, less than 6 × 6 cm(2) with negative culture were studied. Patients were randomized into two groups of 34 each. Patients in study group received LLLT with conventional therapy and those in control group were treated with conventional therapy alone. Healing or percentage reduction in ulcer area over a period of 15 days after commencement of treatment was recorded.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24082586

Evaluation of low level laser therapy in reducing diabetic polyneuropathy related pain and sensorimotor disorders.

Bashiri H1. - Acta Med Iran. 2013 Sep 9;51(8):543-7. ()
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Intro: Over the past three decades physicians have used light level laser therapy (LLLT) for the management and the treatment of diabetic peripheral neuropathy and have obtained results that calls for further investigations. This study aimed to investigate the effectiveness of LLLT in treatment of pain symptoms in patients with diabetic polyneuropathy. In this study 60 patients with diabetic peripheral neuropathy were matched based on their sex, age, BMI, type of diabetes, duration of diabetes, and duration of pain, and randomized to case and control groups based on their established scores on the visual analog scale (VAS) and the Toronto clinical scoring system (TCSS). Cases received laser therapy with wavelength of 78 nm and 2.5 j/cm2 two times a week, each time for 5 min, for one month. During the same period, controls received sham laser therapy. Comparing the differences between the two groups' VAS and TCSS mean scores before the intervention with that of the 2 weeks and 4 weeks after the intervention we were able to see a statistically significant difference between the two groups (P<0.05). On the other hand, when we compared their VAS and TCSS mean scores 4 weeks and 2 weeks after the intervention we did not find any statistically significant difference between the two groups. We achieved the same results when we examined cases' and controls' pre and post VAS and TCSS scores independent from each other; no improvement in the assessment based on their 2 and 4 weeks comparisons tests. Laser therapy resulted in improved neuropathy outcomes in diabetic patients who received it relative to the group that received sham therapy, evaluating before and after LLLT assessments. Further studies are needed to test types of lasers, as well as different dosage and exposure levels required in different phase of neuropathic care, so as to obtain reproducible results.

Background: Over the past three decades physicians have used light level laser therapy (LLLT) for the management and the treatment of diabetic peripheral neuropathy and have obtained results that calls for further investigations. This study aimed to investigate the effectiveness of LLLT in treatment of pain symptoms in patients with diabetic polyneuropathy. In this study 60 patients with diabetic peripheral neuropathy were matched based on their sex, age, BMI, type of diabetes, duration of diabetes, and duration of pain, and randomized to case and control groups based on their established scores on the visual analog scale (VAS) and the Toronto clinical scoring system (TCSS). Cases received laser therapy with wavelength of 78 nm and 2.5 j/cm2 two times a week, each time for 5 min, for one month. During the same period, controls received sham laser therapy. Comparing the differences between the two groups' VAS and TCSS mean scores before the intervention with that of the 2 weeks and 4 weeks after the intervention we were able to see a statistically significant difference between the two groups (P<0.05). On the other hand, when we compared their VAS and TCSS mean scores 4 weeks and 2 weeks after the intervention we did not find any statistically significant difference between the two groups. We achieved the same results when we examined cases' and controls' pre and post VAS and TCSS scores independent from each other; no improvement in the assessment based on their 2 and 4 weeks comparisons tests. Laser therapy resulted in improved neuropathy outcomes in diabetic patients who received it relative to the group that received sham therapy, evaluating before and after LLLT assessments. Further studies are needed to test types of lasers, as well as different dosage and exposure levels required in different phase of neuropathic care, so as to obtain reproducible results.

Abstract: Abstract Over the past three decades physicians have used light level laser therapy (LLLT) for the management and the treatment of diabetic peripheral neuropathy and have obtained results that calls for further investigations. This study aimed to investigate the effectiveness of LLLT in treatment of pain symptoms in patients with diabetic polyneuropathy. In this study 60 patients with diabetic peripheral neuropathy were matched based on their sex, age, BMI, type of diabetes, duration of diabetes, and duration of pain, and randomized to case and control groups based on their established scores on the visual analog scale (VAS) and the Toronto clinical scoring system (TCSS). Cases received laser therapy with wavelength of 78 nm and 2.5 j/cm2 two times a week, each time for 5 min, for one month. During the same period, controls received sham laser therapy. Comparing the differences between the two groups' VAS and TCSS mean scores before the intervention with that of the 2 weeks and 4 weeks after the intervention we were able to see a statistically significant difference between the two groups (P<0.05). On the other hand, when we compared their VAS and TCSS mean scores 4 weeks and 2 weeks after the intervention we did not find any statistically significant difference between the two groups. We achieved the same results when we examined cases' and controls' pre and post VAS and TCSS scores independent from each other; no improvement in the assessment based on their 2 and 4 weeks comparisons tests. Laser therapy resulted in improved neuropathy outcomes in diabetic patients who received it relative to the group that received sham therapy, evaluating before and after LLLT assessments. Further studies are needed to test types of lasers, as well as different dosage and exposure levels required in different phase of neuropathic care, so as to obtain reproducible results.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/24026991

The effects of low-level laser irradiation on bone tissue in diabetic rats.

Patrocínio-Silva TL1, de Souza AM, Goulart RL, Pegorari CF, Oliveira JR, Fernandes K, Magri A, Pereira RM, Araki DR, Nagaoka MR, Parizotto NA, Rennó AC. - Lasers Med Sci. 2014 Jul;29(4):1357-64. doi: 10.1007/s10103-013-1418-y. Epub 2013 Aug 29. ()
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Intro: Diabetes mellitus (DM) leads to a decrease in bone mass and increase the risk of osteoporosis and in this context, many treatments have shown to accelerate bone metabolism. It seems that low-level laser therapy (LLLT) is able of stimulating osteoblast activity and produced increased biomechanical properties. However, its effects on bone in diabetic rats are not fully elucidated. The aim of this study was to evaluate the effects of LLLT on bone formation, immunoexpression of osteogenic factors, biomechanical properties and densitometric parameters in diabetic rats. Thirty male Wistar rats were randomly distributed into three experimental groups: control group, diabetic group, and laser-treated diabetic group. DM was induced by streptozotocin (STZ) and after 1 week laser treatment started. An 830-nm laser was used, performed for 18 sessions, during 6 weeks. At the end of the experiment, animals were euthanized and tibias and femurs were defleshed for analysis. Extensive resorptive areas as a result of osteoclasts activity were noticed in DG when compared to control. Laser-treated animals showed an increased cortical area. The immunohistochemical analysis revealed that LLLT produced an increased RUNX-2 expression compared to other groups. Similar RANK-L immunoexpression was observed for all experimental groups. In addition, laser irradiation produced a statistically increase in fracture force, bone mineral content (BMC) and bone mineral density compared to DG. The results of this study indicate that the STZ model was efficient in inducing DM 1 and producing a decrease in cortical diameter, biomechanical properties and in densitometric variables. In addition, it seems that LLLT stimulated bone metabolism, decreased resorptive areas, increased RUNX-2 expression, cortical area, fracture force, BMD, and BMC. Further studies should be developed to provide additional information concerning the mechanisms of action of laser therapy in diabetic bone in experimental and clinical trials.

Background: Diabetes mellitus (DM) leads to a decrease in bone mass and increase the risk of osteoporosis and in this context, many treatments have shown to accelerate bone metabolism. It seems that low-level laser therapy (LLLT) is able of stimulating osteoblast activity and produced increased biomechanical properties. However, its effects on bone in diabetic rats are not fully elucidated. The aim of this study was to evaluate the effects of LLLT on bone formation, immunoexpression of osteogenic factors, biomechanical properties and densitometric parameters in diabetic rats. Thirty male Wistar rats were randomly distributed into three experimental groups: control group, diabetic group, and laser-treated diabetic group. DM was induced by streptozotocin (STZ) and after 1 week laser treatment started. An 830-nm laser was used, performed for 18 sessions, during 6 weeks. At the end of the experiment, animals were euthanized and tibias and femurs were defleshed for analysis. Extensive resorptive areas as a result of osteoclasts activity were noticed in DG when compared to control. Laser-treated animals showed an increased cortical area. The immunohistochemical analysis revealed that LLLT produced an increased RUNX-2 expression compared to other groups. Similar RANK-L immunoexpression was observed for all experimental groups. In addition, laser irradiation produced a statistically increase in fracture force, bone mineral content (BMC) and bone mineral density compared to DG. The results of this study indicate that the STZ model was efficient in inducing DM 1 and producing a decrease in cortical diameter, biomechanical properties and in densitometric variables. In addition, it seems that LLLT stimulated bone metabolism, decreased resorptive areas, increased RUNX-2 expression, cortical area, fracture force, BMD, and BMC. Further studies should be developed to provide additional information concerning the mechanisms of action of laser therapy in diabetic bone in experimental and clinical trials.

Abstract: Abstract Diabetes mellitus (DM) leads to a decrease in bone mass and increase the risk of osteoporosis and in this context, many treatments have shown to accelerate bone metabolism. It seems that low-level laser therapy (LLLT) is able of stimulating osteoblast activity and produced increased biomechanical properties. However, its effects on bone in diabetic rats are not fully elucidated. The aim of this study was to evaluate the effects of LLLT on bone formation, immunoexpression of osteogenic factors, biomechanical properties and densitometric parameters in diabetic rats. Thirty male Wistar rats were randomly distributed into three experimental groups: control group, diabetic group, and laser-treated diabetic group. DM was induced by streptozotocin (STZ) and after 1 week laser treatment started. An 830-nm laser was used, performed for 18 sessions, during 6 weeks. At the end of the experiment, animals were euthanized and tibias and femurs were defleshed for analysis. Extensive resorptive areas as a result of osteoclasts activity were noticed in DG when compared to control. Laser-treated animals showed an increased cortical area. The immunohistochemical analysis revealed that LLLT produced an increased RUNX-2 expression compared to other groups. Similar RANK-L immunoexpression was observed for all experimental groups. In addition, laser irradiation produced a statistically increase in fracture force, bone mineral content (BMC) and bone mineral density compared to DG. The results of this study indicate that the STZ model was efficient in inducing DM 1 and producing a decrease in cortical diameter, biomechanical properties and in densitometric variables. In addition, it seems that LLLT stimulated bone metabolism, decreased resorptive areas, increased RUNX-2 expression, cortical area, fracture force, BMD, and BMC. Further studies should be developed to provide additional information concerning the mechanisms of action of laser therapy in diabetic bone in experimental and clinical trials.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23990218

The evolving paradigm for the treatment of diabetic macular edema.

Telander D1, Hunter A, Hariprasad SM. - Ophthalmic Surg Lasers Imaging Retina. 2013 Jul-Aug;44(4):324-8. doi: 10.3928/23258160-20130715-02. ()
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Abstract: PMID: 23883266 [PubMed - indexed for MEDLINE] Share on Facebook Share on Twitter Share on Google+

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23883266

The effects of low-level laser therapy on palatal mucoperiosteal wound healing and oxidative stress status in experimental diabetic rats.

Firat ET1, Dağ A, Günay A, Kaya B, Karadede Mİ, Kanay BE, Ketani A, Evliyaoğlu O, Uysal E. - Photomed Laser Surg. 2013 Jul;31(7):315-21. doi: 10.1089/pho.2012.3406. Epub 2013 Jun 21. ()
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Intro: The biostimulation effects of low-level laser therapy (LLLT) have recently been demonstrated. In this study, we aimed to investigate the effects of LLLT on palatal mucoperiostal wound healing and oxidative stress status in experimental diabetic rats.

Background: The biostimulation effects of low-level laser therapy (LLLT) have recently been demonstrated. In this study, we aimed to investigate the effects of LLLT on palatal mucoperiostal wound healing and oxidative stress status in experimental diabetic rats.

Abstract: Abstract OBJECTIVE: The biostimulation effects of low-level laser therapy (LLLT) have recently been demonstrated. In this study, we aimed to investigate the effects of LLLT on palatal mucoperiostal wound healing and oxidative stress status in experimental diabetic rats. MATERIALS AND METHODS: Forty-two male Wistar rats that weighed 250-300 g were used in this study. Experimental diabetes was induced in all of the rats using streptozotocin. A standardized full thickness wound was made in the mucoperiosteum of the hard palates of the rats using a 3 mm biopsy punch. The rats were divided into groups: 1 (control group, non- irradiated), and 2 (experimental group, irradiated). Treatment using a GaAlAs laser at a wavelength of 940 nm and at dose of 10 J/cm(2) began after surgery, and was repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were killed on the 7th, 14th, and 21st day after surgery. Biopsies were performed for the histological analysis and blood samples were collected by cardiac puncture for biochemical analysis. RESULTS: The histopathological findings revealed reduced numbers of inflammatory cells, and increased mitotic activity of fibroblasts, collagen synthesis, and vascularization in rats in group 2. The total oxidative status was significantly decreased in the laser-treated group on the 21st day. CONCLUSIONS: LLLT elicits a positive healing effect on palatal mucoperiostal wounds, and modulates the oxidative status in experimental diabetic rats.

Methods: Forty-two male Wistar rats that weighed 250-300 g were used in this study. Experimental diabetes was induced in all of the rats using streptozotocin. A standardized full thickness wound was made in the mucoperiosteum of the hard palates of the rats using a 3 mm biopsy punch. The rats were divided into groups: 1 (control group, non- irradiated), and 2 (experimental group, irradiated). Treatment using a GaAlAs laser at a wavelength of 940 nm and at dose of 10 J/cm(2) began after surgery, and was repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were killed on the 7th, 14th, and 21st day after surgery. Biopsies were performed for the histological analysis and blood samples were collected by cardiac puncture for biochemical analysis.

Results: The histopathological findings revealed reduced numbers of inflammatory cells, and increased mitotic activity of fibroblasts, collagen synthesis, and vascularization in rats in group 2. The total oxidative status was significantly decreased in the laser-treated group on the 21st day.

Conclusions: LLLT elicits a positive healing effect on palatal mucoperiostal wounds, and modulates the oxidative status in experimental diabetic rats.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23789588

Photobiomodulation of surgical wound dehiscence in a diabetic individual by low-level laser therapy following median sternotomy.

Dixit S1, Maiya A, Umakanth S, Borkar S. - Indian J Palliat Care. 2013 Jan;19(1):71-5. doi: 10.4103/0973-1075.110242. ()
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Intro: In this single case study, we attempt to outline the possible effect of low-level laser therapy (LLLT) on delayed wound healing and pain in chronic dehiscent sternotomy of a diabetic individual. The methods that were employed to evaluate changes pre and post irradiation were wound photography, wound area measurement, pressure ulcer scale of healing (PUSH), and visual analogue scale (VAS) for pain. After irradiation, proliferation of healthy granulation tissue was observed with decrease in scores of PUSH for sternal dehiscence and VAS for bilateral shoulders and sternal dehiscence. We found that LLLT irradiation could be a novel method of treatment for chronic sternal dehiscence following coronary artery bypass grafting, as it augments wound healing with an early closure of the wound deficit. Hence, this might be translated into an early functional rehabilitation and decreased pain perception of an individual following surgical complication.

Background: In this single case study, we attempt to outline the possible effect of low-level laser therapy (LLLT) on delayed wound healing and pain in chronic dehiscent sternotomy of a diabetic individual. The methods that were employed to evaluate changes pre and post irradiation were wound photography, wound area measurement, pressure ulcer scale of healing (PUSH), and visual analogue scale (VAS) for pain. After irradiation, proliferation of healthy granulation tissue was observed with decrease in scores of PUSH for sternal dehiscence and VAS for bilateral shoulders and sternal dehiscence. We found that LLLT irradiation could be a novel method of treatment for chronic sternal dehiscence following coronary artery bypass grafting, as it augments wound healing with an early closure of the wound deficit. Hence, this might be translated into an early functional rehabilitation and decreased pain perception of an individual following surgical complication.

Abstract: Abstract In this single case study, we attempt to outline the possible effect of low-level laser therapy (LLLT) on delayed wound healing and pain in chronic dehiscent sternotomy of a diabetic individual. The methods that were employed to evaluate changes pre and post irradiation were wound photography, wound area measurement, pressure ulcer scale of healing (PUSH), and visual analogue scale (VAS) for pain. After irradiation, proliferation of healthy granulation tissue was observed with decrease in scores of PUSH for sternal dehiscence and VAS for bilateral shoulders and sternal dehiscence. We found that LLLT irradiation could be a novel method of treatment for chronic sternal dehiscence following coronary artery bypass grafting, as it augments wound healing with an early closure of the wound deficit. Hence, this might be translated into an early functional rehabilitation and decreased pain perception of an individual following surgical complication.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23766600

Subthreshold laser therapy for diabetic macular edema: metabolic and safety issues.

Vujosevic S1, Martini F, Convento E, Longhin E, Kotsafti O, Parrozzani R, Midena E. - Curr Med Chem. 2013;20(26):3267-71. ()
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Intro: To review the most important metabolic effects and clinical safety data of subthreshold micropulse diode laser (D-MPL) in diabetic macular edema (DME).

Background: To review the most important metabolic effects and clinical safety data of subthreshold micropulse diode laser (D-MPL) in diabetic macular edema (DME).

Abstract: Abstract PURPOSE: To review the most important metabolic effects and clinical safety data of subthreshold micropulse diode laser (D-MPL) in diabetic macular edema (DME). METHODS: Review of the literature about the mechanisms of action and role of D-MPL in DME. RESULTS: The MPL treatment does not damage the retina and is selectively absorbed by the retinal pigment epithelium (RPE). MPL stimulates secretion of different protective cytokines by the RPE. No visible laser spots on the retina were noted on any fundus image modality in different studies, and there were no changes of the outer retina integrity. Mean central retinal sensitivity (RS) increased in subthreshold micropulse diode laser group compared to standard ETDRS photocoagulation group. CONCLUSIONS: MPL is a new, promising treatment option in DME, with both infrared and yellow wavelengths using the less aggressive duty cycle (5%) and fixed power parameters. It appears to be safe from morphologic and functional point of view in mild center involving DME.

Methods: Review of the literature about the mechanisms of action and role of D-MPL in DME.

Results: The MPL treatment does not damage the retina and is selectively absorbed by the retinal pigment epithelium (RPE). MPL stimulates secretion of different protective cytokines by the RPE. No visible laser spots on the retina were noted on any fundus image modality in different studies, and there were no changes of the outer retina integrity. Mean central retinal sensitivity (RS) increased in subthreshold micropulse diode laser group compared to standard ETDRS photocoagulation group.

Conclusions: MPL is a new, promising treatment option in DME, with both infrared and yellow wavelengths using the less aggressive duty cycle (5%) and fixed power parameters. It appears to be safe from morphologic and functional point of view in mild center involving DME.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23745552

Testing infrared laser phototherapy (810 nm) to ameliorate diabetes: irradiation on body parts of diabetic mice.

Peplow PV1, Baxter GD. - Lasers Surg Med. 2013 Apr;45(4):240-5. doi: 10.1002/lsm.22130. Epub 2013 Apr 8. ()
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Intro: Irradiation of left flank of genetic diabetic mice with 660 nm wavelength laser, 100 mW, 20 seconds/day for 7 days did not significantly alter blood plasma glucose compared to nonirradiated controls. Infrared light would provide for a greater amount of photoenergy penetrating the skin and muscle. Genetic diabetic mice were irradiated with 810 nm wavelength laser to test for antidiabetic effect.

Background: Irradiation of left flank of genetic diabetic mice with 660 nm wavelength laser, 100 mW, 20 seconds/day for 7 days did not significantly alter blood plasma glucose compared to nonirradiated controls. Infrared light would provide for a greater amount of photoenergy penetrating the skin and muscle. Genetic diabetic mice were irradiated with 810 nm wavelength laser to test for antidiabetic effect.

Abstract: Abstract BACKGROUND AND OBJECTIVES: Irradiation of left flank of genetic diabetic mice with 660 nm wavelength laser, 100 mW, 20 seconds/day for 7 days did not significantly alter blood plasma glucose compared to nonirradiated controls. Infrared light would provide for a greater amount of photoenergy penetrating the skin and muscle. Genetic diabetic mice were irradiated with 810 nm wavelength laser to test for antidiabetic effect. MATERIALS AND METHODS: Sixty-five diabetic mice were used. Body weight and water intake of mice were measured daily for 7 days prior to start of treatment (Day 0). Mice were irradiated with 810 nm wavelength laser, 50 mW, 40 seconds/day, 7 days on left flank (n = 11), mid-upper abdomen (n = 14), or left inguinal region (n = 14); some mice were not irradiated (control, n = 26). Body weight and water intake of mice were measured to Day 7. On Day 7, mice were fasted for 4 hours, anesthetized with sodium pentobarbitone (s.c.) and blood collected by cardiac puncture into EDTA-treated tubes. Blood plasma was assayed for glucose and fructosamine. Blood was collected and assayed from nonirradiated nondiabetic mice (n = 12). RESULTS: On Day 7 body weight was significantly lower and water intake significantly higher compared to Day 0 for diabetic mice irradiated on left flank (40.7 ± 0.5 vs. 42.2 ± 0.4 g, 28.2 ± 1.5 vs. 23.4 ± 1.5 g, respectively); there was no significant change for diabetic mice irradiated on mid-upper abdomen or left inguinal region and also for nonirradiated diabetic mice. On Day 7 blood plasma glucose levels for irradiated diabetic mice were not significantly different to nonirradiated diabetic mice. Blood plasma fructosamine level of diabetic mice irradiated on left inguinal region was significantly lower than for nonirradiated diabetic mice (312 ± 6 vs. 377 ± 15 µmol/L); for diabetic mice irradiated on left flank or mid-upper abdomen (362 ± 22, 357 ± 19 µmol/L) it was not significantly different to nonirradiated diabetic mice. CONCLUSION: Irradiation of left inguinal region in diabetic mice with 810 nm laser has potential to ameliorate diabetes as shown by decreased blood plasma fructosamine. Copyright © 2013 Wiley Periodicals, Inc.

Methods: Sixty-five diabetic mice were used. Body weight and water intake of mice were measured daily for 7 days prior to start of treatment (Day 0). Mice were irradiated with 810 nm wavelength laser, 50 mW, 40 seconds/day, 7 days on left flank (n = 11), mid-upper abdomen (n = 14), or left inguinal region (n = 14); some mice were not irradiated (control, n = 26). Body weight and water intake of mice were measured to Day 7. On Day 7, mice were fasted for 4 hours, anesthetized with sodium pentobarbitone (s.c.) and blood collected by cardiac puncture into EDTA-treated tubes. Blood plasma was assayed for glucose and fructosamine. Blood was collected and assayed from nonirradiated nondiabetic mice (n = 12).

Results: On Day 7 body weight was significantly lower and water intake significantly higher compared to Day 0 for diabetic mice irradiated on left flank (40.7 ± 0.5 vs. 42.2 ± 0.4 g, 28.2 ± 1.5 vs. 23.4 ± 1.5 g, respectively); there was no significant change for diabetic mice irradiated on mid-upper abdomen or left inguinal region and also for nonirradiated diabetic mice. On Day 7 blood plasma glucose levels for irradiated diabetic mice were not significantly different to nonirradiated diabetic mice. Blood plasma fructosamine level of diabetic mice irradiated on left inguinal region was significantly lower than for nonirradiated diabetic mice (312 ± 6 vs. 377 ± 15 µmol/L); for diabetic mice irradiated on left flank or mid-upper abdomen (362 ± 22, 357 ± 19 µmol/L) it was not significantly different to nonirradiated diabetic mice.

Conclusions: Irradiation of left inguinal region in diabetic mice with 810 nm laser has potential to ameliorate diabetes as shown by decreased blood plasma fructosamine.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23568826

Effects of pulsed infra-red low level-laser irradiation on mast cells number and degranulation in open skin wound healing of healthy and streptozotocin-induced diabetic rats.

Fathabadie FF1, Bayat M, Amini A, Bayat M, Rezaie F. - J Cosmet Laser Ther. 2013 Dec;15(6):294-304. doi: 10.3109/14764172.2013.764435. Epub 2013 Mar 6. ()
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Intro: Low-level laser therapy (LLLT) has been reported to be capable of changing mast cell numbers and degranulation in experimental wounds.

Background: Low-level laser therapy (LLLT) has been reported to be capable of changing mast cell numbers and degranulation in experimental wounds.

Abstract: Abstract INTRODUCTION: Low-level laser therapy (LLLT) has been reported to be capable of changing mast cell numbers and degranulation in experimental wounds. OBJECTIVE: We conducted a study on the influence of pulsed LLLT on mast cells in wounds of non-diabetic and diabetic rats. METHODS: Thirty-six rats were randomly divided into non-diabetic and diabetic groups. Type 1 diabetes milletes (DM) was induced in rats of the diabetic group by administration of streptozotocin (STZ). We inflicted two wounds in each rat. The first wound in both non-diabetic and diabetic groups was treated with an 890-nm laser, having pulse frequency of 80 Hz and energy density of 0.2 J/cm(2). Mast cell numbers and degranulation of all subgroups were assessed at 4, 7, and 15 days after the infliction of the wounds. RESULTS AND CONCLUSION: According to the paired t-test, the total number of laser-treated mast cells was significantly higher than that of the placebos in the non-diabetic groups on days 4 and 15. The total number of laser-treated mast cells was significantly higher than that of the placebos in the diabetic groups on days 4 and 15. The number of granulated mast cells was significantly higher than that of degranulated mast cells for all laser-treated mast cells and placebo mast cells of the non-diabetic and diabetic groups.

Methods: We conducted a study on the influence of pulsed LLLT on mast cells in wounds of non-diabetic and diabetic rats.

Results: Thirty-six rats were randomly divided into non-diabetic and diabetic groups. Type 1 diabetes milletes (DM) was induced in rats of the diabetic group by administration of streptozotocin (STZ). We inflicted two wounds in each rat. The first wound in both non-diabetic and diabetic groups was treated with an 890-nm laser, having pulse frequency of 80 Hz and energy density of 0.2 J/cm(2). Mast cell numbers and degranulation of all subgroups were assessed at 4, 7, and 15 days after the infliction of the wounds.

Conclusions: According to the paired t-test, the total number of laser-treated mast cells was significantly higher than that of the placebos in the non-diabetic groups on days 4 and 15. The total number of laser-treated mast cells was significantly higher than that of the placebos in the diabetic groups on days 4 and 15. The number of granulated mast cells was significantly higher than that of degranulated mast cells for all laser-treated mast cells and placebo mast cells of the non-diabetic and diabetic groups.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23463989

Wound-healing effects of low-level laser therapy in diabetic rats involve the modulation of MMP-2 and MMP-9 and the redistribution of collagen types I and III.

Aparecida Da Silva A1, Leal-Junior EC, Alves AC, Rambo CS, Dos Santos SA, Vieira RP, De Carvalho Pde T. - J Cosmet Laser Ther. 2013 Aug;15(4):210-6. doi: 10.3109/14764172.2012.761345. Epub 2013 Mar 6. ()
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Intro: The present study aimed to determine if LLLT restores the balance between mRNA expression of matrix metalloproteinases (MMP-2 and MMP-9) and also the balance between collagen types I and III during the healing process of diabetic wounds. One hundred and twenty male Wistar rats were distributed in Control (untreated non-diabetic rats: UND); Laser (laser treated in non-diabetic rats: LTND); Diabetic (diabetic rats non-laser treated rats: UD); and Diabetic+ Laser (diabetic rats laser treated: DLT) groups. The diabetes model using streptozotocin efficiently induced diabetes, as demonstrated through increased levels of blood glucose. Diode laser (50 mW, 660 nm, 4 J/cm(2), 80 s) was applied a single time after scare induction. Twenty-four hours after LLLT application, rats were euthanized, the scarred areas were collected for MMP-2 and MMP-9 mRNA analysis and also for histological analysis (inflammation and types I and III collagen). The results demonstrated that scare in untreated diabetic rats significantly increased the MMP-2 and MMP-9 expression compared with that in non-diabetic rats (p < 0.05), while LLLT significantly reduced MMP-2 and MMP-9 expression compared with that in untreated diabetic rats (p < 0.05). To conclude, the results also showed that LLLT was able to alter the expression of MMP-9 as well as accelerate the production of collagen and increase the total percentage of collagen type III in diabetic animals.

Background: The present study aimed to determine if LLLT restores the balance between mRNA expression of matrix metalloproteinases (MMP-2 and MMP-9) and also the balance between collagen types I and III during the healing process of diabetic wounds. One hundred and twenty male Wistar rats were distributed in Control (untreated non-diabetic rats: UND); Laser (laser treated in non-diabetic rats: LTND); Diabetic (diabetic rats non-laser treated rats: UD); and Diabetic+ Laser (diabetic rats laser treated: DLT) groups. The diabetes model using streptozotocin efficiently induced diabetes, as demonstrated through increased levels of blood glucose. Diode laser (50 mW, 660 nm, 4 J/cm(2), 80 s) was applied a single time after scare induction. Twenty-four hours after LLLT application, rats were euthanized, the scarred areas were collected for MMP-2 and MMP-9 mRNA analysis and also for histological analysis (inflammation and types I and III collagen). The results demonstrated that scare in untreated diabetic rats significantly increased the MMP-2 and MMP-9 expression compared with that in non-diabetic rats (p < 0.05), while LLLT significantly reduced MMP-2 and MMP-9 expression compared with that in untreated diabetic rats (p < 0.05). To conclude, the results also showed that LLLT was able to alter the expression of MMP-9 as well as accelerate the production of collagen and increase the total percentage of collagen type III in diabetic animals.

Abstract: Abstract The present study aimed to determine if LLLT restores the balance between mRNA expression of matrix metalloproteinases (MMP-2 and MMP-9) and also the balance between collagen types I and III during the healing process of diabetic wounds. One hundred and twenty male Wistar rats were distributed in Control (untreated non-diabetic rats: UND); Laser (laser treated in non-diabetic rats: LTND); Diabetic (diabetic rats non-laser treated rats: UD); and Diabetic+ Laser (diabetic rats laser treated: DLT) groups. The diabetes model using streptozotocin efficiently induced diabetes, as demonstrated through increased levels of blood glucose. Diode laser (50 mW, 660 nm, 4 J/cm(2), 80 s) was applied a single time after scare induction. Twenty-four hours after LLLT application, rats were euthanized, the scarred areas were collected for MMP-2 and MMP-9 mRNA analysis and also for histological analysis (inflammation and types I and III collagen). The results demonstrated that scare in untreated diabetic rats significantly increased the MMP-2 and MMP-9 expression compared with that in non-diabetic rats (p < 0.05), while LLLT significantly reduced MMP-2 and MMP-9 expression compared with that in untreated diabetic rats (p < 0.05). To conclude, the results also showed that LLLT was able to alter the expression of MMP-9 as well as accelerate the production of collagen and increase the total percentage of collagen type III in diabetic animals.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23463906

Comparison of natural course, intravitreal triamcinolone and macular laser photocoagulation for treatment of mild diabetic macular edema.

Kwon SI1, Baek SU, Park IW. - Int J Med Sci. 2013;10(3):243-9. doi: 10.7150/ijms.3971. Epub 2013 Jan 21. ()
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Intro: To assess the natural course of the mild diabetic macular edema(DME) and to compare the visual outcomes with the patients with receiving either macular laser photocoagulation or intravitreal injection of triamcinolone acetonide(IVTA).

Background: To assess the natural course of the mild diabetic macular edema(DME) and to compare the visual outcomes with the patients with receiving either macular laser photocoagulation or intravitreal injection of triamcinolone acetonide(IVTA).

Abstract: Abstract PURPOSE: To assess the natural course of the mild diabetic macular edema(DME) and to compare the visual outcomes with the patients with receiving either macular laser photocoagulation or intravitreal injection of triamcinolone acetonide(IVTA). METHODS: 28 eyes with central macular thickness (CMT) of between 250 to 300µm were followed without treatment and 48 eyes with CMT between 300 to 500µm had been divided into 3 subgroups according to treatment. We evaluated the best corrected visual acuity (BCVA) and CMT of natural course group and compared the BCVA and CMT of the patients who had been treated with IVTA or macular laser treatment. RESULTS: The eyes with DME between 250 to 300µm showed no significant change in BCVA and CMT at 6 month. Among the eyes with DME between 300 to 500µm, all 3 subgroups showed no statistically significant change of BCVA at any follow up period and no significant difference was revealed among the subgroups. All subgroups showed significant reduction of CMT after 1 month and maintained until final follow-up and there was no significant difference among subgroups. CONCLUSIONS: Mild DME between 250 to 500µm did not show significant worsening of BCVA or macular edema without any specific treatment.

Methods: 28 eyes with central macular thickness (CMT) of between 250 to 300µm were followed without treatment and 48 eyes with CMT between 300 to 500µm had been divided into 3 subgroups according to treatment. We evaluated the best corrected visual acuity (BCVA) and CMT of natural course group and compared the BCVA and CMT of the patients who had been treated with IVTA or macular laser treatment.

Results: The eyes with DME between 250 to 300µm showed no significant change in BCVA and CMT at 6 month. Among the eyes with DME between 300 to 500µm, all 3 subgroups showed no statistically significant change of BCVA at any follow up period and no significant difference was revealed among the subgroups. All subgroups showed significant reduction of CMT after 1 month and maintained until final follow-up and there was no significant difference among subgroups.

Conclusions: Mild DME between 250 to 500µm did not show significant worsening of BCVA or macular edema without any specific treatment.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23372430

A metabolomic study on the effect of intravascular laser blood irradiation on type 2 diabetic patients.

Kazemi Khoo N1, Iravani A, Arjmand M, Vahabi F, Lajevardi M, Akrami SM, Zamani Z. - Lasers Med Sci. 2013 Nov;28(6):1527-32. doi: 10.1007/s10103-012-1247-4. Epub 2013 Jan 29. ()
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Intro: Intravenous laser blood irradiation (ILBI) is widely applied in the treatment of different pathologies including diabetes mellitus. The aim of this study is to evaluate the effects of ILBI on the metabolites of blood in diabetic type 2 patients using metabolomics. We compared blood samples of nine diabetic type 2 patients, using metabolomics, before and after ILBI with blue light laser. The results showed significant decrease in glucose, glucose 6 phosphate, dehydroascorbic acid, R-3-hydroxybutyric acid, L-histidine, and L-alanine and significant increase in L-arginine level in blood and blood sugar in the patients have reduced significantly (p < 0.05). This study clearly demonstrated a significant positive effect of ILBI on metabolites of blood in diabetic type 2 patients. These findings support the therapeutic potential of ILBI in diabetic patients.

Background: Intravenous laser blood irradiation (ILBI) is widely applied in the treatment of different pathologies including diabetes mellitus. The aim of this study is to evaluate the effects of ILBI on the metabolites of blood in diabetic type 2 patients using metabolomics. We compared blood samples of nine diabetic type 2 patients, using metabolomics, before and after ILBI with blue light laser. The results showed significant decrease in glucose, glucose 6 phosphate, dehydroascorbic acid, R-3-hydroxybutyric acid, L-histidine, and L-alanine and significant increase in L-arginine level in blood and blood sugar in the patients have reduced significantly (p < 0.05). This study clearly demonstrated a significant positive effect of ILBI on metabolites of blood in diabetic type 2 patients. These findings support the therapeutic potential of ILBI in diabetic patients.

Abstract: Abstract Intravenous laser blood irradiation (ILBI) is widely applied in the treatment of different pathologies including diabetes mellitus. The aim of this study is to evaluate the effects of ILBI on the metabolites of blood in diabetic type 2 patients using metabolomics. We compared blood samples of nine diabetic type 2 patients, using metabolomics, before and after ILBI with blue light laser. The results showed significant decrease in glucose, glucose 6 phosphate, dehydroascorbic acid, R-3-hydroxybutyric acid, L-histidine, and L-alanine and significant increase in L-arginine level in blood and blood sugar in the patients have reduced significantly (p < 0.05). This study clearly demonstrated a significant positive effect of ILBI on metabolites of blood in diabetic type 2 patients. These findings support the therapeutic potential of ILBI in diabetic patients.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23358875

Low-intensity laser irradiation at 660 nm stimulates transcription of genes involved in the electron transport chain.

Masha RT1, Houreld NN, Abrahamse H. - Photomed Laser Surg. 2013 Feb;31(2):47-53. doi: 10.1089/pho.2012.3369. Epub 2012 Dec 16. ()
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Intro: Low-intensity laser irradiation (LILI) has been shown to stimulate cellular functions leading to increased adenosine triphosphate (ATP) synthesis. This study was undertaken to evaluate the effect of LILI on genes involved in the mitochondrial electron transport chain (ETC, complexes I-IV) and oxidative phosphorylation (ATP synthase).

Background: Low-intensity laser irradiation (LILI) has been shown to stimulate cellular functions leading to increased adenosine triphosphate (ATP) synthesis. This study was undertaken to evaluate the effect of LILI on genes involved in the mitochondrial electron transport chain (ETC, complexes I-IV) and oxidative phosphorylation (ATP synthase).

Abstract: Abstract BACKGROUND DATA: Low-intensity laser irradiation (LILI) has been shown to stimulate cellular functions leading to increased adenosine triphosphate (ATP) synthesis. This study was undertaken to evaluate the effect of LILI on genes involved in the mitochondrial electron transport chain (ETC, complexes I-IV) and oxidative phosphorylation (ATP synthase). METHODS: Four human skin fibroblast cell models were used in this study: normal non-irradiated cells were used as controls while wounded, diabetic wounded, and ischemic cells were irradiated. Cells were irradiated with a 660 nm diode laser with a fluence of 5 J/cm(2) and gene expression determined by quantitative real-time reverse transcription (RT) polymerase chain reaction (PCR). RESULTS: LILI upregulated cytochrome c oxidase subunit VIb polypeptide 2 (COX6B2), cytochrome c oxidase subunit VIc (COX6C), and pyrophosphatase (inorganic) 1 (PPA1) in diabetic wounded cells; COX6C, ATP synthase, H+transporting, mitochondrial Fo complex, subunit B1 (ATP5F1), nicotinamide adenine dinucleotide (NADH) dehydrogenase (ubiquinone) 1 alpha subcomplex, 11 (NDUFA11), and NADH dehydrogenase (ubiquinone) Fe-S protein 7 (NDUFS7) in wounded cells; and ATPase, H+/K+ exchanging, beta polypeptide (ATP4B), and ATP synthase, H+ transporting, mitochondrial Fo complex, subunit C2 (subunit 9) (ATP5G2) in ischemic cells. CONCLUSIONS: LILI at 660 nm stimulates the upregulation of genes coding for subunits of enzymes involved in complexes I and IV and ATP synthase.

Methods: Four human skin fibroblast cell models were used in this study: normal non-irradiated cells were used as controls while wounded, diabetic wounded, and ischemic cells were irradiated. Cells were irradiated with a 660 nm diode laser with a fluence of 5 J/cm(2) and gene expression determined by quantitative real-time reverse transcription (RT) polymerase chain reaction (PCR).

Results: LILI upregulated cytochrome c oxidase subunit VIb polypeptide 2 (COX6B2), cytochrome c oxidase subunit VIc (COX6C), and pyrophosphatase (inorganic) 1 (PPA1) in diabetic wounded cells; COX6C, ATP synthase, H+transporting, mitochondrial Fo complex, subunit B1 (ATP5F1), nicotinamide adenine dinucleotide (NADH) dehydrogenase (ubiquinone) 1 alpha subcomplex, 11 (NDUFA11), and NADH dehydrogenase (ubiquinone) Fe-S protein 7 (NDUFS7) in wounded cells; and ATPase, H+/K+ exchanging, beta polypeptide (ATP4B), and ATP synthase, H+ transporting, mitochondrial Fo complex, subunit C2 (subunit 9) (ATP5G2) in ischemic cells.

Conclusions: LILI at 660 nm stimulates the upregulation of genes coding for subunits of enzymes involved in complexes I and IV and ATP synthase.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23240874

Gene expression and release of growth factors during delayed wound healing: a review of studies in diabetic animals and possible combined laser phototherapy and growth factor treatment to enhance healing.

- Photomed Laser Surg. 2012 Nov;30(11):617-36. doi: 10.1089/pho.2012.3312. Epub 2012 Oct 17. ()
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Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23075146

Gene expression and release of growth factors during delayed wound healing: a review of studies in diabetic animals and possible combined laser phototherapy and growth factor treatment to enhance healing.

Peplow PV1, Baxter GD. - Photomed Laser Surg. 2012 Nov;30(11):617-36. doi: 10.1089/pho.2012.3312. Epub 2012 Oct 17. ()
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Intro: The purposes of this study were: to review studies of growth factors in cutaneous wounds of animals with diabetes to identify those factors with altered gene expression and content compared with nondiabetic animals; and to explore which deficiencies of growth factors in diabetic wounds may or may not be improved by laser irradiation.

Background: The purposes of this study were: to review studies of growth factors in cutaneous wounds of animals with diabetes to identify those factors with altered gene expression and content compared with nondiabetic animals; and to explore which deficiencies of growth factors in diabetic wounds may or may not be improved by laser irradiation.

Abstract: Abstract OBJECTIVE: The purposes of this study were: to review studies of growth factors in cutaneous wounds of animals with diabetes to identify those factors with altered gene expression and content compared with nondiabetic animals; and to explore which deficiencies of growth factors in diabetic wounds may or may not be improved by laser irradiation. BACKGROUND DATA: Wound healing is compromised in diabetes. Decreased production and/or increased destruction of growth factors may be responsible. Laser irradiation can increase the gene expression and release of certain growth factors by cells. METHODS: Research articles investigating growth factor expression in wounds of nondiabetic and diabetic mice and rats published through September 2011 were retrieved from library sources, PubMed databases, reference lists of articles, and searches of relevant journals. RESULTS: Vascular endothelial growth factor (VEGF), placental growth factor (PlGF), keratinocyte growth factor (KGF), fibroblast growth factor 1 (FGF-1), FGF-2, insulin-like growth factor 1 (IGF-1), IGF-2, transforming growth factor beta (TGF-β), and nerve growth factor (NGF) had decreased gene expression and content in early phases of healing for diabetic wounds. Gene expression of KGF, IGF-1, and IGF-2 was delayed, whereas that of FGF-1 and FGF-2 occurred earlier, in diabetic compared with nondiabetic wounds. CONCLUSIONS: Growth factor administration combined with laser irradiation may provide an effective therapy to maximize healing of diabetic wounds.

Methods: Wound healing is compromised in diabetes. Decreased production and/or increased destruction of growth factors may be responsible. Laser irradiation can increase the gene expression and release of certain growth factors by cells.

Results: Research articles investigating growth factor expression in wounds of nondiabetic and diabetic mice and rats published through September 2011 were retrieved from library sources, PubMed databases, reference lists of articles, and searches of relevant journals.

Conclusions: Vascular endothelial growth factor (VEGF), placental growth factor (PlGF), keratinocyte growth factor (KGF), fibroblast growth factor 1 (FGF-1), FGF-2, insulin-like growth factor 1 (IGF-1), IGF-2, transforming growth factor beta (TGF-β), and nerve growth factor (NGF) had decreased gene expression and content in early phases of healing for diabetic wounds. Gene expression of KGF, IGF-1, and IGF-2 was delayed, whereas that of FGF-1 and FGF-2 occurred earlier, in diabetic compared with nondiabetic wounds.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23075146

Collagen production in diabetic wounded fibroblasts in response to low-intensity laser irradiation at 660 nm.

Ayuk SM1, Houreld NN, Abrahamse H. - Diabetes Technol Ther. 2012 Dec;14(12):1110-7. doi: 10.1089/dia.2012.0125. Epub 2012 Oct 11. ()
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Intro: Collagen type I (Col-I) is a major component of the extracellular matrix and is important in wound healing processes. Several studies have shown that low-intensity laser irradiation (LILI) biostimulates Col-I synthesis both in vitro and in vivo. This study aimed to determine if LILI affects collagen production and related cellular responses in an in vitro diabetic wounded fibroblast model.

Background: Collagen type I (Col-I) is a major component of the extracellular matrix and is important in wound healing processes. Several studies have shown that low-intensity laser irradiation (LILI) biostimulates Col-I synthesis both in vitro and in vivo. This study aimed to determine if LILI affects collagen production and related cellular responses in an in vitro diabetic wounded fibroblast model.

Abstract: Abstract BACKGROUND: Collagen type I (Col-I) is a major component of the extracellular matrix and is important in wound healing processes. Several studies have shown that low-intensity laser irradiation (LILI) biostimulates Col-I synthesis both in vitro and in vivo. This study aimed to determine if LILI affects collagen production and related cellular responses in an in vitro diabetic wounded fibroblast model. MATERIALS AND METHODS: This study was performed on isolated human skin fibroblasts. Different cell models (normal and diabetic wounded) were used. Cells were irradiated with 5 J/cm(2) at a wavelength of 660 nm and incubated for 48 or 72 h. Nonirradiated cells (0 J/cm(2)) were used as controls. Cellular viability (Trypan blue exclusion test), morphology (bright-field microscopy), proliferation [VisionBlueâ„¢ quick cell proliferation assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay], and Col-I (enzyme-linked immunoabsorbent assay) were assessed. RESULTS: Diabetic wounded cells irradiated with 5 J/cm(2) at 660 nm showed a significant increase in cell migration, viability, proliferation, and collagen content. CONCLUSIONS: This study shows that LILI stimulates Col-I synthesis in diabetic wound healing in vitro at 660 nm.

Methods: This study was performed on isolated human skin fibroblasts. Different cell models (normal and diabetic wounded) were used. Cells were irradiated with 5 J/cm(2) at a wavelength of 660 nm and incubated for 48 or 72 h. Nonirradiated cells (0 J/cm(2)) were used as controls. Cellular viability (Trypan blue exclusion test), morphology (bright-field microscopy), proliferation [VisionBlueâ„¢ quick cell proliferation assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay], and Col-I (enzyme-linked immunoabsorbent assay) were assessed.

Results: Diabetic wounded cells irradiated with 5 J/cm(2) at 660 nm showed a significant increase in cell migration, viability, proliferation, and collagen content.

Conclusions: This study shows that LILI stimulates Col-I synthesis in diabetic wound healing in vitro at 660 nm.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23057714

Retina rejuvenation therapy for diabetic macular edema: a pilot study.

Pelosini L1, Hamilton R, Mohamed M, Hamilton AM, Marshall J. - Retina. 2013 Mar;33(3):548-58. doi: 10.1097/IAE.0b013e3182670fea. ()
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Intro: To prospectively investigate the safety and efficacy of a novel frequency-doubled nanosecond-pulsed laser with discontinuous beam energy distribution (2RT, Ellex) for the treatment of diabetic macular edema.

Background: To prospectively investigate the safety and efficacy of a novel frequency-doubled nanosecond-pulsed laser with discontinuous beam energy distribution (2RT, Ellex) for the treatment of diabetic macular edema.

Abstract: Abstract PURPOSE: To prospectively investigate the safety and efficacy of a novel frequency-doubled nanosecond-pulsed laser with discontinuous beam energy distribution (2RT, Ellex) for the treatment of diabetic macular edema. METHODS: Twenty-three consecutive patients (38 eyes) with newly diagnosed diabetic macular edema were recruited and assessed with logarithm of the minimum angle of resolution best-corrected visual acuity, central macular thickness measured with optical coherence tomography (OCT/scanning laser ophthalmoscope, OPKO/OTI), microperimetry, fundus photography, and fundus fluorescein angiography. Macular grid treatments were performed with 2RT laser system by 1 operator. Patients were examined with logarithm of the minimum angle of resolution best-corrected visual acuity, central macular thickness, microperimetry, and fundus photography at 3 weeks and 6 weeks and 3 months and 6 months. Fundus fluorescein angiography was repeated at 3 months and 6 months. RESULTS: Six months postoperatively, 17 patients (28 eyes) completed the study. No complications were identified after 2RT therapy. Intraoperative retinal discoloration was observed in 2 cases, fully resolved at 3 months with no permanent anatomical or functional changes. Mean logarithm of the minimum angle of resolution visual acuity improved from 20/44 at baseline to 20/27 at 6 months. The change in best-corrected visual acuity was significant (P = 0.0190). Central macular thickness in the central 1-mm subfield, retinal exudates and vascular leakage decreased in the majority of patients at 6 months (46, 41, and 55%, respectively), although the change from baseline was not statistically significant. Microperimetry confirmed photoreceptor integrity and showed a trend of improvement that correlated with decreased central macular thickness. CONCLUSION: For the first time, we achieved a beneficial effect on diabetic macular edema without the side effects of conventional laser therapy. The efficacy of this system in comparison with standard argon laser photocoagulation and in the treatment of other conditions affecting the retinal pigment epithelium needs further investigation.

Methods: Twenty-three consecutive patients (38 eyes) with newly diagnosed diabetic macular edema were recruited and assessed with logarithm of the minimum angle of resolution best-corrected visual acuity, central macular thickness measured with optical coherence tomography (OCT/scanning laser ophthalmoscope, OPKO/OTI), microperimetry, fundus photography, and fundus fluorescein angiography. Macular grid treatments were performed with 2RT laser system by 1 operator. Patients were examined with logarithm of the minimum angle of resolution best-corrected visual acuity, central macular thickness, microperimetry, and fundus photography at 3 weeks and 6 weeks and 3 months and 6 months. Fundus fluorescein angiography was repeated at 3 months and 6 months.

Results: Six months postoperatively, 17 patients (28 eyes) completed the study. No complications were identified after 2RT therapy. Intraoperative retinal discoloration was observed in 2 cases, fully resolved at 3 months with no permanent anatomical or functional changes. Mean logarithm of the minimum angle of resolution visual acuity improved from 20/44 at baseline to 20/27 at 6 months. The change in best-corrected visual acuity was significant (P = 0.0190). Central macular thickness in the central 1-mm subfield, retinal exudates and vascular leakage decreased in the majority of patients at 6 months (46, 41, and 55%, respectively), although the change from baseline was not statistically significant. Microperimetry confirmed photoreceptor integrity and showed a trend of improvement that correlated with decreased central macular thickness.

Conclusions: For the first time, we achieved a beneficial effect on diabetic macular edema without the side effects of conventional laser therapy. The efficacy of this system in comparison with standard argon laser photocoagulation and in the treatment of other conditions affecting the retinal pigment epithelium needs further investigation.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/23023529

Electrophysical therapy for managing diabetic foot ulcers: a systematic review.

Kwan RL1, Cheing GL, Vong SK, Lo SK. - Int Wound J. 2013 Apr;10(2):121-31. doi: 10.1111/j.1742-481X.2012.01085.x. Epub 2012 Sep 7. ()
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Intro: To systematically assess published reports on the efficacy of electrophysical therapy in the treatment of diabetic foot ulcers, including electrical stimulation, low-level laser therapy, therapeutic ultrasound and electromagnetic therapy. Databases searched included MEDLINE, CINAHL, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) from 1966 to 2011. Studies reviewed included only randomised controlled trials (RCTs) on treatment with electrophysical modalities compared with sham, conventional treatment or other electrophysical modalities. Information extracted were objective measures of healing and data useful for the calculation of effect size. Eight RCTs were eventually included in the critical appraisal, with a combined total of 325 participants. Five studies were conducted on electrical stimulation, two on phototherapy and one on ultrasound. All studies reported that the experimental group was significantly more favourable than the control or sham group. The pooled estimate of the number of healed ulcers of the three studies on electrical stimulation compared to the control or sham electrical stimulation showed statistical significance [mean difference of 2·8 (95% CI = 1·5-5·5, P = 0·002] in favour of electrical stimulation. The results indicated potential benefit of using electrophysical therapy for managing diabetic foot ulcers. However, due to the small number of trials ever conducted, the possibility of any harmful effects cannot be ruled out, and high-quality trials with larger sample sizes are warranted.

Background: To systematically assess published reports on the efficacy of electrophysical therapy in the treatment of diabetic foot ulcers, including electrical stimulation, low-level laser therapy, therapeutic ultrasound and electromagnetic therapy. Databases searched included MEDLINE, CINAHL, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) from 1966 to 2011. Studies reviewed included only randomised controlled trials (RCTs) on treatment with electrophysical modalities compared with sham, conventional treatment or other electrophysical modalities. Information extracted were objective measures of healing and data useful for the calculation of effect size. Eight RCTs were eventually included in the critical appraisal, with a combined total of 325 participants. Five studies were conducted on electrical stimulation, two on phototherapy and one on ultrasound. All studies reported that the experimental group was significantly more favourable than the control or sham group. The pooled estimate of the number of healed ulcers of the three studies on electrical stimulation compared to the control or sham electrical stimulation showed statistical significance [mean difference of 2·8 (95% CI = 1·5-5·5, P = 0·002] in favour of electrical stimulation. The results indicated potential benefit of using electrophysical therapy for managing diabetic foot ulcers. However, due to the small number of trials ever conducted, the possibility of any harmful effects cannot be ruled out, and high-quality trials with larger sample sizes are warranted.

Abstract: Abstract To systematically assess published reports on the efficacy of electrophysical therapy in the treatment of diabetic foot ulcers, including electrical stimulation, low-level laser therapy, therapeutic ultrasound and electromagnetic therapy. Databases searched included MEDLINE, CINAHL, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) from 1966 to 2011. Studies reviewed included only randomised controlled trials (RCTs) on treatment with electrophysical modalities compared with sham, conventional treatment or other electrophysical modalities. Information extracted were objective measures of healing and data useful for the calculation of effect size. Eight RCTs were eventually included in the critical appraisal, with a combined total of 325 participants. Five studies were conducted on electrical stimulation, two on phototherapy and one on ultrasound. All studies reported that the experimental group was significantly more favourable than the control or sham group. The pooled estimate of the number of healed ulcers of the three studies on electrical stimulation compared to the control or sham electrical stimulation showed statistical significance [mean difference of 2·8 (95% CI = 1·5-5·5, P = 0·002] in favour of electrical stimulation. The results indicated potential benefit of using electrophysical therapy for managing diabetic foot ulcers. However, due to the small number of trials ever conducted, the possibility of any harmful effects cannot be ruled out, and high-quality trials with larger sample sizes are warranted. © 2012 The Authors. International Wound Journal © 2012 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Methods: © 2012 The Authors. International Wound Journal © 2012 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22958779

[Low-level laser therapy in the treatment of diabetic ulcers: an evidence problem].

[Article in Portuguese] - Acta Med Port. 2011 Dec;24 Suppl 4:875-80. Epub 2011 Dec 31. ()
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Background: Diabetes Mellitus is the leading cause of lower limb amputation, representing a significant economic cost for health services. The development of diabetic ulcers is a main risk factor for amputations, which have a high mortality rate at five years. The ischemia caused by macrovascular disease is a key pathophysiological factor in the development of ischemic ulcers. Existing treatments are prolonged and associated with high rates of failure and relapse, requiring the combination of multiple therapeutic modalities. Lowlevel laser therapy has been used as an adjuvant therapy for diabetic foot ulcers, since the 1960's, due to its hypothetical stimulating effects over microcirculation and tissue repair.

Abstract: Author information 1Serviço de Medicina Física e de Reabilitação, Centro Hospitalar de Lisboa Central, Lisboa, Portugal.

Methods: Identification of published scientific studies through a literature search on PubMed, The Cochrane Library and Cochrane Controlled Trials Register.

Results: Existing evidence is favourable for in vitro cell models, but conflicting in animal models and human populations. There is significant methodological heterogeneity, which may be responsible for discordant results. Guidelines are proposed for future studies in this area, including the detailed characterization of ulcers and the parameters of laser treatment. Well-controlled studies, randomized and double-blind are needed. Accordingly to the primum non nocere, laser therapy can and should be used as adjunctive therapy in the treatment of diabetic foot, because it isn't invasive, has low costs and is a fast therapy without significant adverse effects.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22863495

Laser irradiation affects enzymatic antioxidant system of streptozotocin-induced diabetic rats.

Ibuki FK1, Simões A, Nicolau J, Nogueira FN. - Lasers Med Sci. 2013 May;28(3):911-8. doi: 10.1007/s10103-012-1173-5. Epub 2012 Aug 7. ()
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Intro: The aim of the present study was to analyze the effect of low-power laser irradiation in the antioxidant enzymatic system of submandibular (SMG) and parotid (PG) salivary glands of streptozotocin-induced diabetic rats. The animals were randomly divided into six groups: three diabetic groups (D0, D5, and D20) and three non-diabetic groups (C0, C5, and C20), according to laser dose received (0, 5, and 20 J/cm(2), respectively). Areas of approximately 1 cm(2) were demarcated in the salivary glands (each parotid and both submandibular glands) and after irradiated according to Simões et.al. (Lasers Med Sci 24:202-208, 2009). A diode laser (660 nm/100 mW) was used, with laser beam spot of 0.0177 cm(2). The group treated with 5 J/cm(2) laser dose was subjected to irradiation for 1 min and 4 s (total irradiation time) and the group treated with 20 J/cm(2) laser dose was subjected to irradiation for 4 min and 16 s. Twenty-four hours after irradiation the animals were euthanized and the salivary glands were removed for biochemical analysis. The total antioxidant values (TA), the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase enzymes were determined. SOD and CAT activities, as well as TA were higher in SMG of irradiated diabetic rats. However, in SMG of non-diabetic rats, laser irradiation decreased TA values and led to an increase in the CAT activity. In addition, there was a decrease in the activity of CAT in PG of diabetic and non-diabetic animals after laser irradiation. According to the results of the present study, low-power laser irradiation can affect the enzymatic antioxidant system of salivary glands of streptozotocin-induced diabetic rats.

Background: The aim of the present study was to analyze the effect of low-power laser irradiation in the antioxidant enzymatic system of submandibular (SMG) and parotid (PG) salivary glands of streptozotocin-induced diabetic rats. The animals were randomly divided into six groups: three diabetic groups (D0, D5, and D20) and three non-diabetic groups (C0, C5, and C20), according to laser dose received (0, 5, and 20 J/cm(2), respectively). Areas of approximately 1 cm(2) were demarcated in the salivary glands (each parotid and both submandibular glands) and after irradiated according to Simões et.al. (Lasers Med Sci 24:202-208, 2009). A diode laser (660 nm/100 mW) was used, with laser beam spot of 0.0177 cm(2). The group treated with 5 J/cm(2) laser dose was subjected to irradiation for 1 min and 4 s (total irradiation time) and the group treated with 20 J/cm(2) laser dose was subjected to irradiation for 4 min and 16 s. Twenty-four hours after irradiation the animals were euthanized and the salivary glands were removed for biochemical analysis. The total antioxidant values (TA), the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase enzymes were determined. SOD and CAT activities, as well as TA were higher in SMG of irradiated diabetic rats. However, in SMG of non-diabetic rats, laser irradiation decreased TA values and led to an increase in the CAT activity. In addition, there was a decrease in the activity of CAT in PG of diabetic and non-diabetic animals after laser irradiation. According to the results of the present study, low-power laser irradiation can affect the enzymatic antioxidant system of salivary glands of streptozotocin-induced diabetic rats.

Abstract: Abstract The aim of the present study was to analyze the effect of low-power laser irradiation in the antioxidant enzymatic system of submandibular (SMG) and parotid (PG) salivary glands of streptozotocin-induced diabetic rats. The animals were randomly divided into six groups: three diabetic groups (D0, D5, and D20) and three non-diabetic groups (C0, C5, and C20), according to laser dose received (0, 5, and 20 J/cm(2), respectively). Areas of approximately 1 cm(2) were demarcated in the salivary glands (each parotid and both submandibular glands) and after irradiated according to Simões et.al. (Lasers Med Sci 24:202-208, 2009). A diode laser (660 nm/100 mW) was used, with laser beam spot of 0.0177 cm(2). The group treated with 5 J/cm(2) laser dose was subjected to irradiation for 1 min and 4 s (total irradiation time) and the group treated with 20 J/cm(2) laser dose was subjected to irradiation for 4 min and 16 s. Twenty-four hours after irradiation the animals were euthanized and the salivary glands were removed for biochemical analysis. The total antioxidant values (TA), the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase enzymes were determined. SOD and CAT activities, as well as TA were higher in SMG of irradiated diabetic rats. However, in SMG of non-diabetic rats, laser irradiation decreased TA values and led to an increase in the CAT activity. In addition, there was a decrease in the activity of CAT in PG of diabetic and non-diabetic animals after laser irradiation. According to the results of the present study, low-power laser irradiation can affect the enzymatic antioxidant system of salivary glands of streptozotocin-induced diabetic rats.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22869159

[Pain treatment with low reactive level laser therapy (LLLT)].

[Article in Japanese] - Masui. 2012 Jul;61(7):718-27. ()
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Background: Noninvasive and low reactive level laser (LLLT) is used as one of the light therapies without giving pain to the patient. Therefore, it is used often clinically in pain treatment, orthopedics, plastic surgery, dermatology, and dentistry. In the pain clinic field, it is one of the procedures indispensable to treatment of various pain including postherpetic neuralgia, diabetic neuropathy or myofascial pain. In recent years the mechanism has been gradually elucidated by basic study. The action is on sensory nerve, sympathetic nerve, blood vessel, immunity, inflammation and central nervous system, and is thought to contribute to analgesia. Also, many reports such as action to inhibit "itch", a promotor action of the bone metabolism, and the follicular maturation acceleration action have tested and elucidated these mechanisms, and will add further adaptation that will be new in future. Furthermore, development and downsizing of the free electron laser will promote elucidation of the low response level laser therapy. We expect much in the future of the LLLT.

Abstract: Author information 1Department of Pain Management & Palliative Care Medicine, Kyoto Prefectural University of Medicine, Kyoto.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22860300

Effects of pulsed infra-red low level-laser irradiation on open skin wound healing of healthy and streptozotocin-induced diabetic rats by biomechanical evaluation.

Dadpay M1, Sharifian Z, Bayat M, Bayat M, Dabbagh A. - J Photochem Photobiol B. 2012 Jun 4;111:1-8. doi: 10.1016/j.jphotobiol.2012.03.001. Epub 2012 Mar 16. ()
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Intro: Diabetes is one of the most common causes of delayed wound healing. Low-level laser therapy (LLLT) are one of the therapeutic modalities used for the treatment of wounds. The aim of present study is to evaluate the effect of LLLT in experimentally-induced diabetic rats. Two full thickness skin incisions were made on dorsal regions of each rat. The wounds were randomly divided into laser-treated and placebo. Laser-treated wounds of the healthy (non-diabetic) animals were submitted to a pulsed-infrared 890nm laser with an 80Hz frequency and 0.03J/cm(2) for each wound point in the first healthy group and 0.2J/cm(2) in the second healthy group. Laser-treated wounds of the diabetic animals received the same pulsed-infrared laser treatments as the second group for each wound point. On day 15, a sample from each wound was extracted and submitted for tensile strength evaluation. Laser irradiation with 0.03J/cm(2) significantly decreased the maximum load for wound repair in healthy rats (p=0.015). Laser irradiation with 0.2J/cm(2) significantly increased the maximum load in wounds from the healthy control (p=0.021) and diabetic (p<001) groups. Laser treatments with a pulsed infrared laser at 0.2J/cm(2) significantly accelerated wound healing in both healthy and diabetic rats.

Background: Diabetes is one of the most common causes of delayed wound healing. Low-level laser therapy (LLLT) are one of the therapeutic modalities used for the treatment of wounds. The aim of present study is to evaluate the effect of LLLT in experimentally-induced diabetic rats. Two full thickness skin incisions were made on dorsal regions of each rat. The wounds were randomly divided into laser-treated and placebo. Laser-treated wounds of the healthy (non-diabetic) animals were submitted to a pulsed-infrared 890nm laser with an 80Hz frequency and 0.03J/cm(2) for each wound point in the first healthy group and 0.2J/cm(2) in the second healthy group. Laser-treated wounds of the diabetic animals received the same pulsed-infrared laser treatments as the second group for each wound point. On day 15, a sample from each wound was extracted and submitted for tensile strength evaluation. Laser irradiation with 0.03J/cm(2) significantly decreased the maximum load for wound repair in healthy rats (p=0.015). Laser irradiation with 0.2J/cm(2) significantly increased the maximum load in wounds from the healthy control (p=0.021) and diabetic (p<001) groups. Laser treatments with a pulsed infrared laser at 0.2J/cm(2) significantly accelerated wound healing in both healthy and diabetic rats.

Abstract: Abstract Diabetes is one of the most common causes of delayed wound healing. Low-level laser therapy (LLLT) are one of the therapeutic modalities used for the treatment of wounds. The aim of present study is to evaluate the effect of LLLT in experimentally-induced diabetic rats. Two full thickness skin incisions were made on dorsal regions of each rat. The wounds were randomly divided into laser-treated and placebo. Laser-treated wounds of the healthy (non-diabetic) animals were submitted to a pulsed-infrared 890nm laser with an 80Hz frequency and 0.03J/cm(2) for each wound point in the first healthy group and 0.2J/cm(2) in the second healthy group. Laser-treated wounds of the diabetic animals received the same pulsed-infrared laser treatments as the second group for each wound point. On day 15, a sample from each wound was extracted and submitted for tensile strength evaluation. Laser irradiation with 0.03J/cm(2) significantly decreased the maximum load for wound repair in healthy rats (p=0.015). Laser irradiation with 0.2J/cm(2) significantly increased the maximum load in wounds from the healthy control (p=0.021) and diabetic (p<001) groups. Laser treatments with a pulsed infrared laser at 0.2J/cm(2) significantly accelerated wound healing in both healthy and diabetic rats. Copyright © 2012 Elsevier B.V. All rights reserved.

Methods: Copyright © 2012 Elsevier B.V. All rights reserved.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22494918

Effect of low-level laser therapy on healing of tenotomized Achilles tendon in streptozotocin-induced diabetic rats.

Nouruzian M1, Alidoust M, Bayat M, Bayat M, Akbari M. - Lasers Med Sci. 2013 Feb;28(2):399-405. doi: 10.1007/s10103-012-1074-7. Epub 2012 Feb 28. ()
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Intro: Diabetes mellitus (DM) is associated with musculoskeletal damage. Investigations have indicated that healing of the surgically tenotomized Achilles tendon was considerably augmented following low-level laser therapy (LLLT) in non-diabetic, healthy animals. The aim of the present study was to evaluate the effect of LLLT on the Achilles tendon healing in streptozotocin-induced diabetic (STZ-D) rats via a biomechanical evaluating method. Thirty-three rats were divided into non-diabetic (n = 18) and diabetic (n = 15) groups. DM was induced in the rats by injections of STZ. The right Achilles tendons of all rats were tenotomized 1 month after STZ injections. The two experimental groups (n = 6 for each group) of non-diabetic rats were irradiated with a helium-neon (He-Ne) laser at 2.9 and 11.5 J/cm(2) for ten consecutive days. The two experimental groups of diabetic rats (n = 5 for each group) were irradiated with a He-Ne laser at 2.9 and 4.3 J/cm(2) for ten consecutive days. The tendons were submitted to a tensiometric test. Significant improvements in the maximum stress (MS) values (Newton per square millimeter) were found following LLLT at 2.9 J/cm(2) in both the non-diabetic (p = 0.031) and diabetic (p = 0.019) experimental groups when compared with their control groups. LLLT at 2.9 J/cm(2) to the tenotomized Achilles tendons in the non-diabetic and diabetic rats significantly increased the strength and MS of repairing Achilles tendons in our study.

Background: Diabetes mellitus (DM) is associated with musculoskeletal damage. Investigations have indicated that healing of the surgically tenotomized Achilles tendon was considerably augmented following low-level laser therapy (LLLT) in non-diabetic, healthy animals. The aim of the present study was to evaluate the effect of LLLT on the Achilles tendon healing in streptozotocin-induced diabetic (STZ-D) rats via a biomechanical evaluating method. Thirty-three rats were divided into non-diabetic (n = 18) and diabetic (n = 15) groups. DM was induced in the rats by injections of STZ. The right Achilles tendons of all rats were tenotomized 1 month after STZ injections. The two experimental groups (n = 6 for each group) of non-diabetic rats were irradiated with a helium-neon (He-Ne) laser at 2.9 and 11.5 J/cm(2) for ten consecutive days. The two experimental groups of diabetic rats (n = 5 for each group) were irradiated with a He-Ne laser at 2.9 and 4.3 J/cm(2) for ten consecutive days. The tendons were submitted to a tensiometric test. Significant improvements in the maximum stress (MS) values (Newton per square millimeter) were found following LLLT at 2.9 J/cm(2) in both the non-diabetic (p = 0.031) and diabetic (p = 0.019) experimental groups when compared with their control groups. LLLT at 2.9 J/cm(2) to the tenotomized Achilles tendons in the non-diabetic and diabetic rats significantly increased the strength and MS of repairing Achilles tendons in our study.

Abstract: Abstract Diabetes mellitus (DM) is associated with musculoskeletal damage. Investigations have indicated that healing of the surgically tenotomized Achilles tendon was considerably augmented following low-level laser therapy (LLLT) in non-diabetic, healthy animals. The aim of the present study was to evaluate the effect of LLLT on the Achilles tendon healing in streptozotocin-induced diabetic (STZ-D) rats via a biomechanical evaluating method. Thirty-three rats were divided into non-diabetic (n = 18) and diabetic (n = 15) groups. DM was induced in the rats by injections of STZ. The right Achilles tendons of all rats were tenotomized 1 month after STZ injections. The two experimental groups (n = 6 for each group) of non-diabetic rats were irradiated with a helium-neon (He-Ne) laser at 2.9 and 11.5 J/cm(2) for ten consecutive days. The two experimental groups of diabetic rats (n = 5 for each group) were irradiated with a He-Ne laser at 2.9 and 4.3 J/cm(2) for ten consecutive days. The tendons were submitted to a tensiometric test. Significant improvements in the maximum stress (MS) values (Newton per square millimeter) were found following LLLT at 2.9 J/cm(2) in both the non-diabetic (p = 0.031) and diabetic (p = 0.019) experimental groups when compared with their control groups. LLLT at 2.9 J/cm(2) to the tenotomized Achilles tendons in the non-diabetic and diabetic rats significantly increased the strength and MS of repairing Achilles tendons in our study.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22370620

A histological evaluation of a low-level laser therapy as an adjunct to periodontal therapy in patients with diabetes mellitus.

Obradović R1, Kesić L, Mihailović D, Antić S, Jovanović G, Petrović A, Peševska S. - Lasers Med Sci. 2013 Jan;28(1):19-24. doi: 10.1007/s10103-012-1058-7. Epub 2012 Feb 5. ()
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Intro: Diabetes mellitus (DM) and chronic periodontitis are common chronic diseases in adults in the world population. DM has a strong influence on the oral cavity and represents a risk factor for gingivitis and periodontitis. Low-level laser therapy (LLLT) has proven effective in the reduction of inflammation and swelling. The aim of the present study was to evaluate the efficacy of LLLT in diabetic periodontitis through histological analysis. A total of 300 diabetics with chronic periodontal disease and teeth indicated for extraction were assigned into six equal groups. In the groups 1 and 4, indicated teeth were extracted before treatment, and in the rest of the groups upon completion of the entire treatment. All patients received oral hygiene instructions and full-mouth conservative periodontal treatment. In groups 3 and 6, LLLT was applied (670 nm, 5 mW, 2 J/cm(2), 16 min, 5 days). Histologic findings of gingival tissue treated with LLLT showed expressed healing, as is evident by the absence of inflammatory cells. Tissue edema could not be seen, and the number of blood vessels was reduced. In the gingival lamina, propria pronounced collagenization and homogenization were present. It can be concluded that LLLT has shown efficacy in the treatment of periodontitis in diabetics. Because of more pronounced alterations of periodontium in diabetics, the use of LLLT is of particular importance.

Background: Diabetes mellitus (DM) and chronic periodontitis are common chronic diseases in adults in the world population. DM has a strong influence on the oral cavity and represents a risk factor for gingivitis and periodontitis. Low-level laser therapy (LLLT) has proven effective in the reduction of inflammation and swelling. The aim of the present study was to evaluate the efficacy of LLLT in diabetic periodontitis through histological analysis. A total of 300 diabetics with chronic periodontal disease and teeth indicated for extraction were assigned into six equal groups. In the groups 1 and 4, indicated teeth were extracted before treatment, and in the rest of the groups upon completion of the entire treatment. All patients received oral hygiene instructions and full-mouth conservative periodontal treatment. In groups 3 and 6, LLLT was applied (670 nm, 5 mW, 2 J/cm(2), 16 min, 5 days). Histologic findings of gingival tissue treated with LLLT showed expressed healing, as is evident by the absence of inflammatory cells. Tissue edema could not be seen, and the number of blood vessels was reduced. In the gingival lamina, propria pronounced collagenization and homogenization were present. It can be concluded that LLLT has shown efficacy in the treatment of periodontitis in diabetics. Because of more pronounced alterations of periodontium in diabetics, the use of LLLT is of particular importance.

Abstract: Abstract Diabetes mellitus (DM) and chronic periodontitis are common chronic diseases in adults in the world population. DM has a strong influence on the oral cavity and represents a risk factor for gingivitis and periodontitis. Low-level laser therapy (LLLT) has proven effective in the reduction of inflammation and swelling. The aim of the present study was to evaluate the efficacy of LLLT in diabetic periodontitis through histological analysis. A total of 300 diabetics with chronic periodontal disease and teeth indicated for extraction were assigned into six equal groups. In the groups 1 and 4, indicated teeth were extracted before treatment, and in the rest of the groups upon completion of the entire treatment. All patients received oral hygiene instructions and full-mouth conservative periodontal treatment. In groups 3 and 6, LLLT was applied (670 nm, 5 mW, 2 J/cm(2), 16 min, 5 days). Histologic findings of gingival tissue treated with LLLT showed expressed healing, as is evident by the absence of inflammatory cells. Tissue edema could not be seen, and the number of blood vessels was reduced. In the gingival lamina, propria pronounced collagenization and homogenization were present. It can be concluded that LLLT has shown efficacy in the treatment of periodontitis in diabetics. Because of more pronounced alterations of periodontium in diabetics, the use of LLLT is of particular importance.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22311659

Laser irradiation effect on Staphylococcus aureus and Pseudomonas aeruginosa biofilms isolated from venous leg ulcer.

Baffoni M1, Bessa LJ, Grande R, Di Giulio M, Mongelli M, Ciarelli A, Cellini L. - Int Wound J. 2012 Oct;9(5):517-24. doi: 10.1111/j.1742-481X.2011.00910.x. Epub 2011 Dec 19. ()
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Intro: Chronic wounds, including diabetic foot ulcers, pressure ulcers and venous leg ulcers, represent a significant cause of morbidity in developed countries, predominantly in older patients. The aetiology of these wounds is probably multifactorial, but the role of bacteria in their pathogenesis is still unclear. Moreover, the presence of bacterial biofilms has been considered an important factor responsible for wounds chronicity. We aimed to investigate the laser action as a possible biofilm eradicating strategy, in order to attempt an additional treatment to antibiotic therapy to improve wound healing. In this work, the effect of near-infrared (NIR) laser was evaluated on mono and polymicrobial biofilms produced by two pathogenic bacterial strains, Staphylococcus aureus PECHA10 and Pseudomonas aeruginosa PECHA9, both isolated from a chronic venous leg ulcer. Laser effect was assessed by biomass measurement, colony forming unit count and cell viability assay. It was shown that the laser treatment has not affected the biofilms biomass neither the cell viability, although a small disruptive action was observed in the structure of all biofilms tested. A reduction on cell growth was observed in S. aureus and in polymicrobial biofilms. This work represents an initial in vitro approach to study the influence of NIR laser treatment on bacterial biofilms in order to explain its potentially advantageous effects in the healing process of chronic infected wounds.

Background: Chronic wounds, including diabetic foot ulcers, pressure ulcers and venous leg ulcers, represent a significant cause of morbidity in developed countries, predominantly in older patients. The aetiology of these wounds is probably multifactorial, but the role of bacteria in their pathogenesis is still unclear. Moreover, the presence of bacterial biofilms has been considered an important factor responsible for wounds chronicity. We aimed to investigate the laser action as a possible biofilm eradicating strategy, in order to attempt an additional treatment to antibiotic therapy to improve wound healing. In this work, the effect of near-infrared (NIR) laser was evaluated on mono and polymicrobial biofilms produced by two pathogenic bacterial strains, Staphylococcus aureus PECHA10 and Pseudomonas aeruginosa PECHA9, both isolated from a chronic venous leg ulcer. Laser effect was assessed by biomass measurement, colony forming unit count and cell viability assay. It was shown that the laser treatment has not affected the biofilms biomass neither the cell viability, although a small disruptive action was observed in the structure of all biofilms tested. A reduction on cell growth was observed in S. aureus and in polymicrobial biofilms. This work represents an initial in vitro approach to study the influence of NIR laser treatment on bacterial biofilms in order to explain its potentially advantageous effects in the healing process of chronic infected wounds.

Abstract: Abstract Chronic wounds, including diabetic foot ulcers, pressure ulcers and venous leg ulcers, represent a significant cause of morbidity in developed countries, predominantly in older patients. The aetiology of these wounds is probably multifactorial, but the role of bacteria in their pathogenesis is still unclear. Moreover, the presence of bacterial biofilms has been considered an important factor responsible for wounds chronicity. We aimed to investigate the laser action as a possible biofilm eradicating strategy, in order to attempt an additional treatment to antibiotic therapy to improve wound healing. In this work, the effect of near-infrared (NIR) laser was evaluated on mono and polymicrobial biofilms produced by two pathogenic bacterial strains, Staphylococcus aureus PECHA10 and Pseudomonas aeruginosa PECHA9, both isolated from a chronic venous leg ulcer. Laser effect was assessed by biomass measurement, colony forming unit count and cell viability assay. It was shown that the laser treatment has not affected the biofilms biomass neither the cell viability, although a small disruptive action was observed in the structure of all biofilms tested. A reduction on cell growth was observed in S. aureus and in polymicrobial biofilms. This work represents an initial in vitro approach to study the influence of NIR laser treatment on bacterial biofilms in order to explain its potentially advantageous effects in the healing process of chronic infected wounds. © 2011 The Authors. International Wound Journal © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Methods: © 2011 The Authors. International Wound Journal © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22182280

Laser photostimulation (660 nm) of wound healing in diabetic mice is not brought about by ameliorating diabetes.

Peplow PV1, Chung TY, Baxter GD. - Lasers Surg Med. 2012 Jan;44(1):26-9. doi: 10.1002/lsm.21133. Epub 2011 Nov 22. ()
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Intro: We have used a 660-nm laser diode in genetic diabetic mice to stimulate the healing of wounds covered with a Tegaderm HP dressing that causes a retardation of contraction (splinted wounds). It is possible that the stimulation of healing could be due to possible diabetes-modifying properties of laser light. This has been examined by using the 660 nm laser to irradiate non-wounded diabetic mice with the same dose and at same location as for wounded diabetic mice.

Background: We have used a 660-nm laser diode in genetic diabetic mice to stimulate the healing of wounds covered with a Tegaderm HP dressing that causes a retardation of contraction (splinted wounds). It is possible that the stimulation of healing could be due to possible diabetes-modifying properties of laser light. This has been examined by using the 660 nm laser to irradiate non-wounded diabetic mice with the same dose and at same location as for wounded diabetic mice.

Abstract: Abstract BACKGROUND AND OBJECTIVES: We have used a 660-nm laser diode in genetic diabetic mice to stimulate the healing of wounds covered with a Tegaderm HP dressing that causes a retardation of contraction (splinted wounds). It is possible that the stimulation of healing could be due to possible diabetes-modifying properties of laser light. This has been examined by using the 660 nm laser to irradiate non-wounded diabetic mice with the same dose and at same location as for wounded diabetic mice. MATERIALS AND METHODS: Twenty-two diabetic mice were used and divided into two equal groups. Body weight and water intake of mice were measured daily for 7 days prior to the start of treatment (Day 0). The left flank of mice in the experimental group was irradiated with 660 nm laser, 100 mW, 20 seconds/day, 7 days; for mice in the control group, the left flank was sham-treated with the laser power supply not switched on. Body weight and water intake of mice were measured to Day 14. On Day 14, the mice were fasted for 4 hours, anaesthetized with sodium pentobarbitone (i.p.) and blood collected by cardiac puncture into heparinized tubes. The plasma was assayed for glucose and glycated hemoglobin A1c. RESULTS: There were no significant differences in body weight and water intake over 22 days between mice in the experimental group and control group. On day 14, the mean blood plasma glucose level was not significantly different between the two groups; glycated hemoglobin A1c was not detected in the samples. CONCLUSION: Irradiation of the left flank in diabetic mice with 660 nm laser system does not have a significant hypoglycemic effect, and the laser-stimulated healing of wounds in diabetic mice is due to cellular and biochemical changes in the immediate wound environment. Copyright © 2011 Wiley Periodicals, Inc.

Methods: Twenty-two diabetic mice were used and divided into two equal groups. Body weight and water intake of mice were measured daily for 7 days prior to the start of treatment (Day 0). The left flank of mice in the experimental group was irradiated with 660 nm laser, 100 mW, 20 seconds/day, 7 days; for mice in the control group, the left flank was sham-treated with the laser power supply not switched on. Body weight and water intake of mice were measured to Day 14. On Day 14, the mice were fasted for 4 hours, anaesthetized with sodium pentobarbitone (i.p.) and blood collected by cardiac puncture into heparinized tubes. The plasma was assayed for glucose and glycated hemoglobin A1c.

Results: There were no significant differences in body weight and water intake over 22 days between mice in the experimental group and control group. On day 14, the mean blood plasma glucose level was not significantly different between the two groups; glycated hemoglobin A1c was not detected in the samples.

Conclusions: Irradiation of the left flank in diabetic mice with 660 nm laser system does not have a significant hypoglycemic effect, and the laser-stimulated healing of wounds in diabetic mice is due to cellular and biochemical changes in the immediate wound environment.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/22109569

[Low power laser efficacy in the therapy of inflamed gingive in diabetics with parodontopathy].

[Article in Serbian] - Vojnosanit Pregl. 2011 Aug;68(8):684-9. ()
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Background: There is clear evidence on direct relationship between periodontal disease and diabetes mellitus. Many investigations point out greater prevalence and severity of periodontal disease among diabetic patients. During last decade, low level laser therapy has been used in periodontal therapy. It has biostimulative effect, accelerates wound healing, minimizes pain and swelling, and there is almost no contraindication for its usage. The aim of the paper was to investigate the efficiency of low level laser therapy as adjuvant tool in reduction of gingival inflammation in diabetic patients.

Abstract: Author information 1Medicinski fakultet, Klinika za stomatologiju, Odeljenje za oralnu medicinu i parodontologiju, Nis, Srbija. dr.rada@yahoo.com

Methods: The study incuded 150 participants divided into three groups: group I (50 participants with diabetes mellitus type 1 and periodontal disease), group II (50 participants with diabetes mellitus type 2 and periodontal disease), group III (nondiabetic participants with periodontal disease). Gingival health evaluation was done using gingival index Löe-Silness. Soft and hard deposits were removed, periodontal pockets cleaned and GaA1As low level laser therapy (5 mW) applied five consecutive days. In each patient, low level laser therapy was not applied on the left side of the jaw in order to compare the effects of the applied therapy. After the first, third and fifth therapy and one month after the last visit gingival index was evaluated. Before the first and after the fifth therapy exfoliative cytology of gingiva was done and nuclei areal was analyzed morphometrically.

Results: After all investigated periods, gingival index and nuclei areal were significantly decreased comparing to values before the therapy, at both jaw sides (p < 0.001). After the 1st, 3rd and 5th therapy, the t-test showed a significantly decreased gingival index at the lased side of jaw comparing to non-lased side.

Conclusions: Low level laser therapy is efficient in gingival inflammation elimination and can be proposed as an adjuvant tool in basic periodontal therapy of diabetic patients.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/21991792

Diabetic distal symmetric polyneuropathy: effect of low-intensity laser therapy.

Khamseh ME1, Kazemikho N, Aghili R, Forough B, Lajevardi M, Hashem Dabaghian F, Goushegir A, Malek M. - Lasers Med Sci. 2011 Nov;26(6):831-5. doi: 10.1007/s10103-011-0977-z. Epub 2011 Aug 19. ()
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Intro: Low-intensity laser therapy (LILT) has been considered as a treatment modality in diabetic distal symmetric polyneuropathy (DSP). The aim of this study is to determine the effectiveness of LILT on DSP. We examined 107 subjects with type 2 diabetes for detection of DSP using the Michigan Neuropathy Screening Instrument (MNSI). Seventeen subjects were eligible to be enrolled in the study. Nerve conduction studies (NCS) were performed in all eligible subjects as an objective method to confirm neuropathy. The participants received LILT three times a week for ten sessions. NCSs were reevaluated after completion of the treatment. The absolute changes in NCS parameters were considered to establish the effectiveness of the treatment. Baseline demographics were similar in all participants. The mean differences of NCV parameters were considered for comparison. At the end of the study, the subjects showed a significant increase in neural potential amplitudes (p < 0.05). This study clearly demonstrated a significant positive effect of LILT on improvement of nerve conduction velocity on diabetic distal symmetric polyneuropathy (DSP). This finding supports the therapeutic potential of LILT in DSP.

Background: Low-intensity laser therapy (LILT) has been considered as a treatment modality in diabetic distal symmetric polyneuropathy (DSP). The aim of this study is to determine the effectiveness of LILT on DSP. We examined 107 subjects with type 2 diabetes for detection of DSP using the Michigan Neuropathy Screening Instrument (MNSI). Seventeen subjects were eligible to be enrolled in the study. Nerve conduction studies (NCS) were performed in all eligible subjects as an objective method to confirm neuropathy. The participants received LILT three times a week for ten sessions. NCSs were reevaluated after completion of the treatment. The absolute changes in NCS parameters were considered to establish the effectiveness of the treatment. Baseline demographics were similar in all participants. The mean differences of NCV parameters were considered for comparison. At the end of the study, the subjects showed a significant increase in neural potential amplitudes (p < 0.05). This study clearly demonstrated a significant positive effect of LILT on improvement of nerve conduction velocity on diabetic distal symmetric polyneuropathy (DSP). This finding supports the therapeutic potential of LILT in DSP.

Abstract: Abstract Low-intensity laser therapy (LILT) has been considered as a treatment modality in diabetic distal symmetric polyneuropathy (DSP). The aim of this study is to determine the effectiveness of LILT on DSP. We examined 107 subjects with type 2 diabetes for detection of DSP using the Michigan Neuropathy Screening Instrument (MNSI). Seventeen subjects were eligible to be enrolled in the study. Nerve conduction studies (NCS) were performed in all eligible subjects as an objective method to confirm neuropathy. The participants received LILT three times a week for ten sessions. NCSs were reevaluated after completion of the treatment. The absolute changes in NCS parameters were considered to establish the effectiveness of the treatment. Baseline demographics were similar in all participants. The mean differences of NCV parameters were considered for comparison. At the end of the study, the subjects showed a significant increase in neural potential amplitudes (p < 0.05). This study clearly demonstrated a significant positive effect of LILT on improvement of nerve conduction velocity on diabetic distal symmetric polyneuropathy (DSP). This finding supports the therapeutic potential of LILT in DSP.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/21853320

Effect of 980-nm GaAlAs diode laser irradiation on healing of extraction sockets in streptozotocin-induced diabetic rats: a pilot study.

Park JJ1, Kang KL. - Lasers Med Sci. 2012 Jan;27(1):223-30. doi: 10.1007/s10103-011-0944-8. Epub 2011 Jul 6. ()
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Intro: Low-level laser irradiation can promote the healing process in soft and hard tissue but the precise mechanisms are unclear. In this study, we examined the effect of LLLT (low-level laser therapy) on the healing of extraction sockets in diabetic and healthy rats. Forty-eight Sprague-Dawley rats were divided into normal (n = 24) and diabetic (n = 24) rats, and streptozotocin (STZ) injection was used to induce diabetes in the latter. The left and right maxillary first molars of all the rats were extracted. In the non-diabetic rats, the left extraction sockets were not irradiated (group 1) and the right ones were irradiated daily for 3, 5, 7, and 14 days after extraction with a galium-aluminum-arsenide (GaAlAs) diode laser (group 2), and in the diabetic rats, similarly the left ones were not irradiated (group 3) and the right ones were irradiated (group 4). Specimens acquired at these intervals were examined by hematoxylin and eosin (H&E) staining and reverse transcription polymerase chain reaction (RT-PCR). Histological observations and gene expression analyses revealed that groups 2 (normal rats with LLLT) and 4 (diabetic rats with LLLT) showed faster initial healing and more new alveolar bone formation than group 1 (normal rats without LLLT) and group 3 (diabetic rats without LLLT), respectively. We conclude that 980-nm GaAlAs low-intensity diode laser irradiation is beneficial for the initial stages of alveolar bone healing and for further calcification in both diabetic and normal rats when applied every day at a dose of 13.95 J/cm(2) for 60 s.

Background: Low-level laser irradiation can promote the healing process in soft and hard tissue but the precise mechanisms are unclear. In this study, we examined the effect of LLLT (low-level laser therapy) on the healing of extraction sockets in diabetic and healthy rats. Forty-eight Sprague-Dawley rats were divided into normal (n = 24) and diabetic (n = 24) rats, and streptozotocin (STZ) injection was used to induce diabetes in the latter. The left and right maxillary first molars of all the rats were extracted. In the non-diabetic rats, the left extraction sockets were not irradiated (group 1) and the right ones were irradiated daily for 3, 5, 7, and 14 days after extraction with a galium-aluminum-arsenide (GaAlAs) diode laser (group 2), and in the diabetic rats, similarly the left ones were not irradiated (group 3) and the right ones were irradiated (group 4). Specimens acquired at these intervals were examined by hematoxylin and eosin (H&E) staining and reverse transcription polymerase chain reaction (RT-PCR). Histological observations and gene expression analyses revealed that groups 2 (normal rats with LLLT) and 4 (diabetic rats with LLLT) showed faster initial healing and more new alveolar bone formation than group 1 (normal rats without LLLT) and group 3 (diabetic rats without LLLT), respectively. We conclude that 980-nm GaAlAs low-intensity diode laser irradiation is beneficial for the initial stages of alveolar bone healing and for further calcification in both diabetic and normal rats when applied every day at a dose of 13.95 J/cm(2) for 60 s.

Abstract: Abstract Low-level laser irradiation can promote the healing process in soft and hard tissue but the precise mechanisms are unclear. In this study, we examined the effect of LLLT (low-level laser therapy) on the healing of extraction sockets in diabetic and healthy rats. Forty-eight Sprague-Dawley rats were divided into normal (n = 24) and diabetic (n = 24) rats, and streptozotocin (STZ) injection was used to induce diabetes in the latter. The left and right maxillary first molars of all the rats were extracted. In the non-diabetic rats, the left extraction sockets were not irradiated (group 1) and the right ones were irradiated daily for 3, 5, 7, and 14 days after extraction with a galium-aluminum-arsenide (GaAlAs) diode laser (group 2), and in the diabetic rats, similarly the left ones were not irradiated (group 3) and the right ones were irradiated (group 4). Specimens acquired at these intervals were examined by hematoxylin and eosin (H&E) staining and reverse transcription polymerase chain reaction (RT-PCR). Histological observations and gene expression analyses revealed that groups 2 (normal rats with LLLT) and 4 (diabetic rats with LLLT) showed faster initial healing and more new alveolar bone formation than group 1 (normal rats without LLLT) and group 3 (diabetic rats without LLLT), respectively. We conclude that 980-nm GaAlAs low-intensity diode laser irradiation is beneficial for the initial stages of alveolar bone healing and for further calcification in both diabetic and normal rats when applied every day at a dose of 13.95 J/cm(2) for 60 s.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/21732114

The diabetic foot and leg: combined He-Ne and infrared low-intensity lasers improve skin blood perfusion and prevent potential complications. A prospective study on 30 Egyptian patients.

Saied GM1, Kamel RM, Labib AM, Said MT, Mohamed AZ. - Lasers Med Sci. 2011 Sep;26(5):627-32. doi: 10.1007/s10103-011-0911-4. Epub 2011 Apr 1. ()
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Intro: The objective of this study was to examine skin blood flow in diabetic patients having disease-related skin lesions, and to evaluate possible improvement imposed by low-intensity laser therapy (LILT) as a new treatment modality. Thirty patients (in addition to 15 controls receiving conventional treatment = group II and 15 others receiving no treatment = group III) having diabetes-related skin lesions were tested for skin blood flow by laser Doppler flowmetry. Group I patients received LILT by a specified dosimetry. This was by combined uniform He-Ne and infrared lasers delivered by a scanner over the affected area. This study used a paired t test to determine the significance of blood flow recovery after treatment within each group while Independent t test compared results between the three groups. The level of significance was p < 0.05. The most frequently detected diabetes specific skin lesions were dryness, nail changes, hair loss, infections, itching, and frank eczema-like reactions, mostly in combinations (76%). This pattern appears specific for Egyptians as it is different from data registered in foreign literature. The minimum perfusion flow improved from 16.45 before LILT to 25.94 after, while maximum flow recovered from 32.91 to 48.47 and basal perfusion changed from 24.68 to 34.84 blood perfusion units. The percentage change in perfusion values was 23.17. All these were statistically significant. The study demonstrates that diabetes-linked skin lesions have a special pattern in Egyptians and are apparently caused by deranged skin blood flow .The deficit is measurable by laser flowmetry and can be partially reversed by LILT.

Background: The objective of this study was to examine skin blood flow in diabetic patients having disease-related skin lesions, and to evaluate possible improvement imposed by low-intensity laser therapy (LILT) as a new treatment modality. Thirty patients (in addition to 15 controls receiving conventional treatment = group II and 15 others receiving no treatment = group III) having diabetes-related skin lesions were tested for skin blood flow by laser Doppler flowmetry. Group I patients received LILT by a specified dosimetry. This was by combined uniform He-Ne and infrared lasers delivered by a scanner over the affected area. This study used a paired t test to determine the significance of blood flow recovery after treatment within each group while Independent t test compared results between the three groups. The level of significance was p < 0.05. The most frequently detected diabetes specific skin lesions were dryness, nail changes, hair loss, infections, itching, and frank eczema-like reactions, mostly in combinations (76%). This pattern appears specific for Egyptians as it is different from data registered in foreign literature. The minimum perfusion flow improved from 16.45 before LILT to 25.94 after, while maximum flow recovered from 32.91 to 48.47 and basal perfusion changed from 24.68 to 34.84 blood perfusion units. The percentage change in perfusion values was 23.17. All these were statistically significant. The study demonstrates that diabetes-linked skin lesions have a special pattern in Egyptians and are apparently caused by deranged skin blood flow .The deficit is measurable by laser flowmetry and can be partially reversed by LILT.

Abstract: Abstract The objective of this study was to examine skin blood flow in diabetic patients having disease-related skin lesions, and to evaluate possible improvement imposed by low-intensity laser therapy (LILT) as a new treatment modality. Thirty patients (in addition to 15 controls receiving conventional treatment = group II and 15 others receiving no treatment = group III) having diabetes-related skin lesions were tested for skin blood flow by laser Doppler flowmetry. Group I patients received LILT by a specified dosimetry. This was by combined uniform He-Ne and infrared lasers delivered by a scanner over the affected area. This study used a paired t test to determine the significance of blood flow recovery after treatment within each group while Independent t test compared results between the three groups. The level of significance was p < 0.05. The most frequently detected diabetes specific skin lesions were dryness, nail changes, hair loss, infections, itching, and frank eczema-like reactions, mostly in combinations (76%). This pattern appears specific for Egyptians as it is different from data registered in foreign literature. The minimum perfusion flow improved from 16.45 before LILT to 25.94 after, while maximum flow recovered from 32.91 to 48.47 and basal perfusion changed from 24.68 to 34.84 blood perfusion units. The percentage change in perfusion values was 23.17. All these were statistically significant. The study demonstrates that diabetes-linked skin lesions have a special pattern in Egyptians and are apparently caused by deranged skin blood flow .The deficit is measurable by laser flowmetry and can be partially reversed by LILT.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/21455785

Irradiation at 636 nm positively affects diabetic wounded and hypoxic cells in vitro.

Sekhejane PR1, Houreld NN, Abrahamse H. - Photomed Laser Surg. 2011 Aug;29(8):521-30. doi: 10.1089/pho.2010.2877. Epub 2011 Feb 19. ()
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Intro: This study investigated the effect of low-intensity laser irradiation (LILI) on pro-inflammatory cytokines involved in wound healing processes in diabetes and hypoxia.

Background: This study investigated the effect of low-intensity laser irradiation (LILI) on pro-inflammatory cytokines involved in wound healing processes in diabetes and hypoxia.

Abstract: Abstract OBJECTIVE: This study investigated the effect of low-intensity laser irradiation (LILI) on pro-inflammatory cytokines involved in wound healing processes in diabetes and hypoxia. BACKGROUND DATA: Diabetes is associated with impaired wound healing and a prolonged inflammatory phase. Pro-inflammatory cytokines such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α and IL-6 are elevated in diabetes. LILI has been reported to accelerate wound healing and decrease inflammatory cytokines. METHODS: A human skin fibroblast cell line (WS1) was used in vitro. Cells were exposed to various insults, namely, wounding, and a diabetic or hypoxic environment. Experimental cells were exposed to an energy density of 5 J/cm(2) using a continuous wave 636-nm diode laser at an average power of 95 mW, an illuminated area of 9.05 cm(2), and an irradiance of 11 mW/cm(2) (irradiation time, 476 sec). The effect of laser irradiation on cytokine expression was examined at 1 or 24 h post-irradiation. Cellular morphology, viability, proliferation, and cytokine expression (IL-1β, IL-6, and TNF-α) were investigated. Translocation of nuclear factor-kappa B (NF-κB) was also determined. RESULTS: There was a higher rate of migration in irradiated wounded cultures, and irradiated hypoxic cells showed an improvement in cellular morphology. All cell models showed an increase in proliferation. Normal wounded cells showed a decrease in apoptosis, TNF-α, and IL-1β. Diabetic wounded cells showed an increase in viability and a decrease in apoptosis and IL-1β, whereas hypoxic cells showed an increase in viability and IL-6, and a decrease in apoptosis and TNF-α. NF-κB was translocated into the nucleus post-irradiation. CONCLUSIONS: Phototherapy resulted in hastened wound closure, increased proliferation, and normalization of cellular function. The decrease in the different pro-inflammatory cytokines and NF-κB translocation was model and time dependent. Overall, laser irradiation resulted in a reduction in inflammatory cytokines and directed cells into the cell survival pathway.

Methods: Diabetes is associated with impaired wound healing and a prolonged inflammatory phase. Pro-inflammatory cytokines such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α and IL-6 are elevated in diabetes. LILI has been reported to accelerate wound healing and decrease inflammatory cytokines.

Results: A human skin fibroblast cell line (WS1) was used in vitro. Cells were exposed to various insults, namely, wounding, and a diabetic or hypoxic environment. Experimental cells were exposed to an energy density of 5 J/cm(2) using a continuous wave 636-nm diode laser at an average power of 95 mW, an illuminated area of 9.05 cm(2), and an irradiance of 11 mW/cm(2) (irradiation time, 476 sec). The effect of laser irradiation on cytokine expression was examined at 1 or 24 h post-irradiation. Cellular morphology, viability, proliferation, and cytokine expression (IL-1β, IL-6, and TNF-α) were investigated. Translocation of nuclear factor-kappa B (NF-κB) was also determined.

Conclusions: There was a higher rate of migration in irradiated wounded cultures, and irradiated hypoxic cells showed an improvement in cellular morphology. All cell models showed an increase in proliferation. Normal wounded cells showed a decrease in apoptosis, TNF-α, and IL-1β. Diabetic wounded cells showed an increase in viability and a decrease in apoptosis and IL-1β, whereas hypoxic cells showed an increase in viability and IL-6, and a decrease in apoptosis and TNF-α. NF-κB was translocated into the nucleus post-irradiation.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/21332376

A randomized clinical trial on the effect of low-level laser therapy on chronic diabetic foot wound healing: a preliminary report.

Kaviani A1, Djavid GE, Ataie-Fashtami L, Fateh M, Ghodsi M, Salami M, Zand N, Kashef N, Larijani B. - Photomed Laser Surg. 2011 Feb;29(2):109-14. doi: 10.1089/pho.2009.2680. Epub 2011 Jan 9. ()
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Intro: Low-level laser therapy (LLLT) has been shown to promote chronic wound healing in conditions of reduced microcirculation. In this preliminary study, we report the results of using LLLT to heal foot ulcers in patients with diabetes mellitus.

Background: Low-level laser therapy (LLLT) has been shown to promote chronic wound healing in conditions of reduced microcirculation. In this preliminary study, we report the results of using LLLT to heal foot ulcers in patients with diabetes mellitus.

Abstract: Abstract BACKGROUND AND OBJECTIVES: Low-level laser therapy (LLLT) has been shown to promote chronic wound healing in conditions of reduced microcirculation. In this preliminary study, we report the results of using LLLT to heal foot ulcers in patients with diabetes mellitus. MATERIALS AND METHODS: Twenty-three patients with a diabetic foot wound for at least 3 months were included in this double-blind randomized clinical trial. Patients were randomized to receive placebo treatment (n = 10) or LLLT (n = 13) (685 nm, energy density 10 J/cm(2)) in addition to conventional therapy. Patients were followed for 20 weeks. Ulcer size reduction and the number of patients with complete healing were compared between the LLLT and placebo groups. RESULTS: There were no significant differences in baseline characteristics of patients and foot ulcers receiving LLLT and placebo treatment. At week 4, the size of ulcers decreased significantly in the LLLT group (p = 0.04). After 20 weeks, in the LLLT group, eight patients had complete healing and in the placebo group only three patients experienced complete wound healing. The mean time of complete healing in LLLT patients (11 weeks) was less than that in placebo patients (14 weeks) though the difference was not statistically significant. CONCLUSIONS: The study provides evidence that LLLT can accelerate the healing process of chronic diabetic foot ulcers, and it can be presumed that LLLT may shorten the time period needed to achieve complete healing.

Methods: Twenty-three patients with a diabetic foot wound for at least 3 months were included in this double-blind randomized clinical trial. Patients were randomized to receive placebo treatment (n = 10) or LLLT (n = 13) (685 nm, energy density 10 J/cm(2)) in addition to conventional therapy. Patients were followed for 20 weeks. Ulcer size reduction and the number of patients with complete healing were compared between the LLLT and placebo groups.

Results: There were no significant differences in baseline characteristics of patients and foot ulcers receiving LLLT and placebo treatment. At week 4, the size of ulcers decreased significantly in the LLLT group (p = 0.04). After 20 weeks, in the LLLT group, eight patients had complete healing and in the placebo group only three patients experienced complete wound healing. The mean time of complete healing in LLLT patients (11 weeks) was less than that in placebo patients (14 weeks) though the difference was not statistically significant.

Conclusions: The study provides evidence that LLLT can accelerate the healing process of chronic diabetic foot ulcers, and it can be presumed that LLLT may shorten the time period needed to achieve complete healing.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/21214368

Low-intensity laser irradiation stimulates wound healing in diabetic wounded fibroblast cells (WS1).

Houreld N1, Abrahamse H. - Diabetes Technol Ther. 2010 Dec;12(12):971-8. doi: 10.1089/dia.2010.0039. ()
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Intro: Patients with diabetes suffer from slow-to-heal wounds, which often necessitate amputation. Low-intensity laser irradiation (LILI) has been shown to reduce the healing time in such patients. This study aimed to determine the effect of different wavelengths of LILI on cellular migration, viability, and proliferation in a wounded diabetic cell model.

Background: Patients with diabetes suffer from slow-to-heal wounds, which often necessitate amputation. Low-intensity laser irradiation (LILI) has been shown to reduce the healing time in such patients. This study aimed to determine the effect of different wavelengths of LILI on cellular migration, viability, and proliferation in a wounded diabetic cell model.

Abstract: Abstract BACKGROUND: Patients with diabetes suffer from slow-to-heal wounds, which often necessitate amputation. Low-intensity laser irradiation (LILI) has been shown to reduce the healing time in such patients. This study aimed to determine the effect of different wavelengths of LILI on cellular migration, viability, and proliferation in a wounded diabetic cell model. METHODS: Diabetic wounded and unwounded human skin fibroblast cells (WS1) were irradiated at 632.8, 830, or 1,064 nm with 5 J/cm(2). Cellular morphology and migration were determined microscopically, while cellular viability was determined by ATP luminescence, and proliferation was determined by basic fibroblast growth factor expression and alkaline phosphatase activity. RESULTS: Diabetic wounded cells irradiated at 1,064 nm showed a lesser degree of migration, viability, and proliferation compared to cells irradiated at 632.8 or 830 nm. Cells irradiated at 632.8 nm showed a higher degree of haptotaxis and migration as well as ATP luminescence compared to cells irradiated at 830 nm. CONCLUSIONS: This study showed that LILI of diabetic wounded cells in the visible range (632.8 nm) was more beneficial to wound healing than irradiating the same cells to wavelengths in the infrared range. Cells irradiated at a longer wavelength of 1,064 nm performed worse.

Methods: Diabetic wounded and unwounded human skin fibroblast cells (WS1) were irradiated at 632.8, 830, or 1,064 nm with 5 J/cm(2). Cellular morphology and migration were determined microscopically, while cellular viability was determined by ATP luminescence, and proliferation was determined by basic fibroblast growth factor expression and alkaline phosphatase activity.

Results: Diabetic wounded cells irradiated at 1,064 nm showed a lesser degree of migration, viability, and proliferation compared to cells irradiated at 632.8 or 830 nm. Cells irradiated at 632.8 nm showed a higher degree of haptotaxis and migration as well as ATP luminescence compared to cells irradiated at 830 nm.

Conclusions: This study showed that LILI of diabetic wounded cells in the visible range (632.8 nm) was more beneficial to wound healing than irradiating the same cells to wavelengths in the infrared range. Cells irradiated at a longer wavelength of 1,064 nm performed worse.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/21128844

Laser photobiostimulation of wound healing: defining a dose response for splinted wounds in diabetic mice.

Chung TY1, Peplow PV, Baxter GD. - Lasers Surg Med. 2010 Nov;42(9):656-64. doi: 10.1002/lsm.20981. ()
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Intro: We have used a 660 nm, 80 mW laser diode in genetic diabetic mice to stimulate the healing of wounds covered with a Tegaderm HP dressing that causes a retardation of contraction (splinted wounds). The purpose of our study was to examine the effects of irradiating the wounds for different time intervals in order to determine a dose response relationship.

Background: We have used a 660 nm, 80 mW laser diode in genetic diabetic mice to stimulate the healing of wounds covered with a Tegaderm HP dressing that causes a retardation of contraction (splinted wounds). The purpose of our study was to examine the effects of irradiating the wounds for different time intervals in order to determine a dose response relationship.

Abstract: Abstract BACKGROUND AND OBJECTIVES: We have used a 660 nm, 80 mW laser diode in genetic diabetic mice to stimulate the healing of wounds covered with a Tegaderm HP dressing that causes a retardation of contraction (splinted wounds). The purpose of our study was to examine the effects of irradiating the wounds for different time intervals in order to determine a dose response relationship. MATERIALS AND METHODS: A circular excisional wound was made on the left flank of diabetic mice using a 5-mm skin punch, and covered with a Tegaderm HP dressing. Mice were allocated to four groups in which wounds were irradiated 660 nm, 80 mW for 0, 10, 20, or 40 seconds each day for 7 days. In total, 51 mice were used. Wounds were harvested on day 14 and the healing assessed from hematoxylin-eosin stained sections examined by light microscopy. RESULTS: The wounds were splinted in 40 of the mice, and splinting caused a retardation of healing. The findings for the four treatments showed that irradiation for 20 second/day for 7 days brought about the greatest extent of healing. The wounds healed mainly by re-epithelization and granulation tissue formation. This duration of irradiation represents an energy dose of 1.6 J per irradiation and, for an estimated area of irradiation of 32-43 mm², corresponds to an energy density of 3.7-5.0 J/cm². CONCLUSION: Irradiation with 660 nm, 80 mW at an energy density of 3.7-5.0 J/cm² each day for 7 days caused the maximal stimulation of healing in splinted wounds of diabetic mice. © 2010 Wiley-Liss, Inc.

Methods: A circular excisional wound was made on the left flank of diabetic mice using a 5-mm skin punch, and covered with a Tegaderm HP dressing. Mice were allocated to four groups in which wounds were irradiated 660 nm, 80 mW for 0, 10, 20, or 40 seconds each day for 7 days. In total, 51 mice were used. Wounds were harvested on day 14 and the healing assessed from hematoxylin-eosin stained sections examined by light microscopy.

Results: The wounds were splinted in 40 of the mice, and splinting caused a retardation of healing. The findings for the four treatments showed that irradiation for 20 second/day for 7 days brought about the greatest extent of healing. The wounds healed mainly by re-epithelization and granulation tissue formation. This duration of irradiation represents an energy dose of 1.6 J per irradiation and, for an estimated area of irradiation of 32-43 mm², corresponds to an energy density of 3.7-5.0 J/cm².

Conclusions: Irradiation with 660 nm, 80 mW at an energy density of 3.7-5.0 J/cm² each day for 7 days caused the maximal stimulation of healing in splinted wounds of diabetic mice.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/20976805

A combination of 670 nm and 810 nm diode lasers for wound healing acceleration in diabetic rats.

Jahangiri Noudeh Y1, Shabani M, Vatankhah N, Hashemian SJ, Akbari K. - Photomed Laser Surg. 2010 Oct;28(5):621-7. doi: 10.1089/pho.2009.2634. ()
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Intro: To study the effects of the combination of 670 nm and 810 nm diode lasers on diabetic wound healing parameters in rats.

Background: To study the effects of the combination of 670 nm and 810 nm diode lasers on diabetic wound healing parameters in rats.

Abstract: Abstract OBJECTIVES: To study the effects of the combination of 670 nm and 810 nm diode lasers on diabetic wound healing parameters in rats. BACKGROUND: An alternative to traditional treatment modalities for diabetic ulcers is low-level laser therapy (LLLT). A number of published studies demonstrate the beneficial effects of LLLT, although several other studies also exist which indicate results to the contrary. METHODS: Four groups were present in our study: Diabetic-laser (n = 5), Diabetic-control (n = 4), Nondiabetic-laser (n = 5) and Nondiabetic-control (n = 5) groups. Two intervention (laser) groups underwent low level laser therapy using 670 nm diode laser (500 mW, 10 J, 48 s) in the wound context, and 810 nm diode laser (250 mW, 12 J, 50 s) to the wound margins. The wound area was measured using computer software after digital microscopic photography on days 0, 3, 6, 9, 12, 15, 20, and 24. RESULTS: There were no statistically significant differences between the diabetic and non-diabetic groups in the wound area, percentage of open wound area, and wound healing rate throughout the repeated measurements of the study. After seven days of low level laser therapy in the non-diabetic group, urine excretion was significantly increased in comparison with the control group. CONCLUSION: Overall, our study showed results of measured wound healing parameters that were not significantly different in the LLLT group compared with the control group. The urine volume increase in non-diabetic rats after LLLT was an incidental observation that warrants future study.

Methods: An alternative to traditional treatment modalities for diabetic ulcers is low-level laser therapy (LLLT). A number of published studies demonstrate the beneficial effects of LLLT, although several other studies also exist which indicate results to the contrary.

Results: Four groups were present in our study: Diabetic-laser (n = 5), Diabetic-control (n = 4), Nondiabetic-laser (n = 5) and Nondiabetic-control (n = 5) groups. Two intervention (laser) groups underwent low level laser therapy using 670 nm diode laser (500 mW, 10 J, 48 s) in the wound context, and 810 nm diode laser (250 mW, 12 J, 50 s) to the wound margins. The wound area was measured using computer software after digital microscopic photography on days 0, 3, 6, 9, 12, 15, 20, and 24.

Conclusions: There were no statistically significant differences between the diabetic and non-diabetic groups in the wound area, percentage of open wound area, and wound healing rate throughout the repeated measurements of the study. After seven days of low level laser therapy in the non-diabetic group, urine excretion was significantly increased in comparison with the control group.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/20961229

Testing photobiomodulatory effects of laser irradiation on wound healing: development of an improved model for dressing wounds in mice.

Chung TY1, Peplow PV, Baxter GD. - Photomed Laser Surg. 2010 Oct;28(5):589-96. doi: 10.1089/pho.2009.2641. Epub 2010 Jul 28. ()
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Intro: To develop a suitable method for dressing skin wounds in BKS.Cg-m(+)/(+)Lepr(db) mice for subsequent use in laser irradiation of wounds. The healing of nonirradiated wounds (controls) was examined histologically to provide essential reference data.

Background: To develop a suitable method for dressing skin wounds in BKS.Cg-m(+)/(+)Lepr(db) mice for subsequent use in laser irradiation of wounds. The healing of nonirradiated wounds (controls) was examined histologically to provide essential reference data.

Abstract: Abstract OBJECTIVE: To develop a suitable method for dressing skin wounds in BKS.Cg-m(+)/(+)Lepr(db) mice for subsequent use in laser irradiation of wounds. The healing of nonirradiated wounds (controls) was examined histologically to provide essential reference data. BACKGROUND DATA: Dressing excisional skin wounds in mice has many advantages. However, previous studies using dressings such as Tegaderm W or OpSite, with or without adhesives, have shown that this is not easily achieved. MATERIALS AND METHODS: In a pilot study, a full-thickness wound was made on the left flank in six diabetic and six nondiabetic mice, and five different methods were tried for dressing the wounds with Tegaderm HP to develop an optimized procedure. The optimized procedure was used in subsequent studies, with a total of 23 diabetic and 13 nondiabetic mice being controls for laser-irradiated mice. Measurements of healing outcomes from histologic sections of controls were statistically analyzed. RESULTS: The optimized procedure used Tegaderm HP with Cavilon and Fixomull Stretch strips for the first dressing, and with Mastisol for subsequent dressings. Wound closure by contraction was retarded in a large proportion of diabetic mice (approximately 80%) and a small proportion of nondiabetic mice. These wounds, described as "splinted," healed mainly by epithelial regeneration and granulation tissue formation. CONCLUSION: A simple, easy-to-perform procedure was developed for dressing wounds in diabetic and nondiabetic mice. It was found to cause splinting with wound healing mimicking that in human patients. This model is suitable for examining the effects of different therapies on wound healing, including lasers.

Methods: Dressing excisional skin wounds in mice has many advantages. However, previous studies using dressings such as Tegaderm W or OpSite, with or without adhesives, have shown that this is not easily achieved.

Results: In a pilot study, a full-thickness wound was made on the left flank in six diabetic and six nondiabetic mice, and five different methods were tried for dressing the wounds with Tegaderm HP to develop an optimized procedure. The optimized procedure was used in subsequent studies, with a total of 23 diabetic and 13 nondiabetic mice being controls for laser-irradiated mice. Measurements of healing outcomes from histologic sections of controls were statistically analyzed.

Conclusions: The optimized procedure used Tegaderm HP with Cavilon and Fixomull Stretch strips for the first dressing, and with Mastisol for subsequent dressings. Wound closure by contraction was retarded in a large proportion of diabetic mice (approximately 80%) and a small proportion of nondiabetic mice. These wounds, described as "splinted," healed mainly by epithelial regeneration and granulation tissue formation.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/20666635

Effects of low-level light therapy on streptozotocin-induced diabetic kidney.

Lim J1, Sanders RA, Snyder AC, Eells JT, Henshel DS, Watkins JB 3rd. - J Photochem Photobiol B. 2010 May 3;99(2):105-10. doi: 10.1016/j.jphotobiol.2010.03.002. Epub 2010 Mar 11. ()
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Intro: Hyperglycemia causes oxidative damage in tissues prone to complications in diabetes. Low-level light therapy (LLLT) in the red to near infrared range (630-1000nm) has been shown to accelerate diabetic wound healing. To test the hypothesis that LLLT would attenuate oxidative renal damage in Type I diabetic rats, male Wistar rats were made diabetic with streptozotocin (50mg/kg, ip), and then exposed to 670nm light at a dose of 9J/cm(2) once per day for 14weeks. The activity and expression of catalase and the activity of Na K-ATPase increased in kidneys of light-treated diabetic rats, whereas the activity and expression of glutathione peroxidase and the expression of Na K-ATPase were unchanged. LLLT lowered the values of serum BUN, serum creatinine, and BUN/creatinine ratio. In addition, LLLT augmented the activity and expression of cytochrome c oxidase, a primary photoacceptor molecule in the mitochondrial respiratory chain, and reduced the formation of the DNA adduct 8-hydroxy-2'-deoxyguanosine in kidney. LLLT improved renal function and antioxidant defense capabilities in the kidney of Type I diabetic rats. Thus, 670nm LLLT may be broadly applicable to the amelioration of renal complications induced by diabetes that disrupt antioxidant defense mechanisms.

Background: Hyperglycemia causes oxidative damage in tissues prone to complications in diabetes. Low-level light therapy (LLLT) in the red to near infrared range (630-1000nm) has been shown to accelerate diabetic wound healing. To test the hypothesis that LLLT would attenuate oxidative renal damage in Type I diabetic rats, male Wistar rats were made diabetic with streptozotocin (50mg/kg, ip), and then exposed to 670nm light at a dose of 9J/cm(2) once per day for 14weeks. The activity and expression of catalase and the activity of Na K-ATPase increased in kidneys of light-treated diabetic rats, whereas the activity and expression of glutathione peroxidase and the expression of Na K-ATPase were unchanged. LLLT lowered the values of serum BUN, serum creatinine, and BUN/creatinine ratio. In addition, LLLT augmented the activity and expression of cytochrome c oxidase, a primary photoacceptor molecule in the mitochondrial respiratory chain, and reduced the formation of the DNA adduct 8-hydroxy-2'-deoxyguanosine in kidney. LLLT improved renal function and antioxidant defense capabilities in the kidney of Type I diabetic rats. Thus, 670nm LLLT may be broadly applicable to the amelioration of renal complications induced by diabetes that disrupt antioxidant defense mechanisms.

Abstract: Abstract Hyperglycemia causes oxidative damage in tissues prone to complications in diabetes. Low-level light therapy (LLLT) in the red to near infrared range (630-1000nm) has been shown to accelerate diabetic wound healing. To test the hypothesis that LLLT would attenuate oxidative renal damage in Type I diabetic rats, male Wistar rats were made diabetic with streptozotocin (50mg/kg, ip), and then exposed to 670nm light at a dose of 9J/cm(2) once per day for 14weeks. The activity and expression of catalase and the activity of Na K-ATPase increased in kidneys of light-treated diabetic rats, whereas the activity and expression of glutathione peroxidase and the expression of Na K-ATPase were unchanged. LLLT lowered the values of serum BUN, serum creatinine, and BUN/creatinine ratio. In addition, LLLT augmented the activity and expression of cytochrome c oxidase, a primary photoacceptor molecule in the mitochondrial respiratory chain, and reduced the formation of the DNA adduct 8-hydroxy-2'-deoxyguanosine in kidney. LLLT improved renal function and antioxidant defense capabilities in the kidney of Type I diabetic rats. Thus, 670nm LLLT may be broadly applicable to the amelioration of renal complications induced by diabetes that disrupt antioxidant defense mechanisms. Copyright 2010 Elsevier B.V. All rights reserved.

Methods: Copyright 2010 Elsevier B.V. All rights reserved.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/20356759

Influence of ingaalp laser (660nm) on the healing of skin wounds in diabetic rats.

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The effects of helium-neon light therapy on healing of partial osteotomy of the tibia in streptozotocin induced diabetic rats.

Abdi S1, Bayat M, Javadieh F, Mohsenifar Z, Rezaie F, Bayat M. - Photomed Laser Surg. 2009 Dec;27(6):907-12. doi: 10.1089/pho.2008.2421. ()
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Intro: The effect of light therapy (LT) on surgically created partial osteotomy in streptozotocin (STZ)-induced diabetic rats was examined.

Background: The effect of light therapy (LT) on surgically created partial osteotomy in streptozotocin (STZ)-induced diabetic rats was examined.

Abstract: Abstract OBJECTIVE: The effect of light therapy (LT) on surgically created partial osteotomy in streptozotocin (STZ)-induced diabetic rats was examined. BACKGROUND DATA: LT has been shown to enhance bone repair in healthy human and animal models. MATERIALS AND METHODS: Forty male rats were divided into groups 1 to 5. Diabetes was induced in rats of groups 1, 2, and 3 using an intraperitoneal injection of STZ. All diabetic rats were maintained for 30 days after STZ injection. Under general anesthesia and sterile conditions, a partial transversal standardized osteotomy was made in the mid-portion of the right tibia. The defects in groups 2, 3, and 5 were treated using a helium-neon (He-Ne) laser (632.8 nm, 10 mW, circular beam shape). Groups 1 and 4 were diabetic placebo and normal placebo groups, respectively. A dose of 369.4 J/cm2 for groups 2 and 5 and a dose of 66.8 J/cm2 for group 3 were applied three times a week. Six weeks after surgery, the right tibia was collected. The specimen was subjected to a three-point bending test. RESULTS: LT with 369.4 J/cm2 energy density resulted in significantly greater bending stiffness in group 5 (41.8+/-5.2) than in groups 1 (18.5+/-4.1), 2 (17.7+/-1.6), and 3 (11.5+/-4) (least significant difference (LSD) test, p<0.01, p<0.001, and p<0.001, respectively). LT with 369.4 J/cm2 energy density resulted in a significantly higher stress load in group 5 (10+/-0.4) than in groups 1 (4.9+/-1.5), 2 (5.7+/-0.52), and 3 (3.9+/-1.1) (LSD test, p<0.01, p<0.01, p<0.001, respectively). CONCLUSION: LT with a He-Ne laser in STZ-induced diabetic rats did not enhance bone repair of a partial transversal standardized osteotomy.

Methods: LT has been shown to enhance bone repair in healthy human and animal models.

Results: Forty male rats were divided into groups 1 to 5. Diabetes was induced in rats of groups 1, 2, and 3 using an intraperitoneal injection of STZ. All diabetic rats were maintained for 30 days after STZ injection. Under general anesthesia and sterile conditions, a partial transversal standardized osteotomy was made in the mid-portion of the right tibia. The defects in groups 2, 3, and 5 were treated using a helium-neon (He-Ne) laser (632.8 nm, 10 mW, circular beam shape). Groups 1 and 4 were diabetic placebo and normal placebo groups, respectively. A dose of 369.4 J/cm2 for groups 2 and 5 and a dose of 66.8 J/cm2 for group 3 were applied three times a week. Six weeks after surgery, the right tibia was collected. The specimen was subjected to a three-point bending test.

Conclusions: LT with 369.4 J/cm2 energy density resulted in significantly greater bending stiffness in group 5 (41.8+/-5.2) than in groups 1 (18.5+/-4.1), 2 (17.7+/-1.6), and 3 (11.5+/-4) (least significant difference (LSD) test, p<0.01, p<0.001, and p<0.001, respectively). LT with 369.4 J/cm2 energy density resulted in a significantly higher stress load in group 5 (10+/-0.4) than in groups 1 (4.9+/-1.5), 2 (5.7+/-0.52), and 3 (3.9+/-1.1) (LSD test, p<0.01, p<0.01, p<0.001, respectively).

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/20035603

Laser photobiomodulation of wound healing in diabetic and non-diabetic mice: effects in splinted and unsplinted wounds.

Chung TY1, Peplow PV, Baxter GD. - Photomed Laser Surg. 2010 Apr;28(2):251-61. doi: 10.1089/pho.2009.2493. ()
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Intro: The aim of this investigation was to compare the healing of laser-irradiated and non-irradiated wounds covered by an occlusive dressing in mice.

Background: The aim of this investigation was to compare the healing of laser-irradiated and non-irradiated wounds covered by an occlusive dressing in mice.

Abstract: Abstract OBJECTIVE: The aim of this investigation was to compare the healing of laser-irradiated and non-irradiated wounds covered by an occlusive dressing in mice. BACKGROUND DATA: Many previous studies of the effects of laser irradiation of experimental wounds in mice and rats did not cover the wounds so that healing occurred mainly by contraction. Healing of covered wounds is slower and mimics more closely wound healing in humans. MATERIALS AND METHODS: Forty-seven diabetic and twenty non-diabetic mice were used. A single wound (5 mm diameter) was created on the left flank of each animal and covered by Tegaderm HP dressing (Day 1). Wounds were irradiated (660 nm) for 20 s using a lower power (18 mW) or higher power (80 mW) laser starting immediately post-wounding for seven consecutive days (0.36 or 1.6 J/day); untreated wounds served as controls. Animals were euthanized on Day 8, 10, or 14. Wound specimens were cut and stained using haematoxylin and eosin, and picrosirius red, and examined by microscopy. RESULTS: Results confirmed that wound healing was impaired in diabetic mice. Analysis of the data demonstrated that Tegaderm HP dressing had retarded contraction (splinted the wounds) in a large proportion of diabetic mice and, to a lesser extent, in non-diabetic mice. Healing of splinted wounds was delayed compared to unsplinted wounds, but laser irradiation (1.6 J/day, 7 days) stimulated healing by re-epithelization and granulation tissue formation. CONCLUSION: These are the first findings of laser-mediated stimulation of healing in splinted wounds. Further studies are needed to assess the effects of different constellation sets of laser parameters in this wound model.

Methods: Many previous studies of the effects of laser irradiation of experimental wounds in mice and rats did not cover the wounds so that healing occurred mainly by contraction. Healing of covered wounds is slower and mimics more closely wound healing in humans.

Results: Forty-seven diabetic and twenty non-diabetic mice were used. A single wound (5 mm diameter) was created on the left flank of each animal and covered by Tegaderm HP dressing (Day 1). Wounds were irradiated (660 nm) for 20 s using a lower power (18 mW) or higher power (80 mW) laser starting immediately post-wounding for seven consecutive days (0.36 or 1.6 J/day); untreated wounds served as controls. Animals were euthanized on Day 8, 10, or 14. Wound specimens were cut and stained using haematoxylin and eosin, and picrosirius red, and examined by microscopy.

Conclusions: Results confirmed that wound healing was impaired in diabetic mice. Analysis of the data demonstrated that Tegaderm HP dressing had retarded contraction (splinted the wounds) in a large proportion of diabetic mice and, to a lesser extent, in non-diabetic mice. Healing of splinted wounds was delayed compared to unsplinted wounds, but laser irradiation (1.6 J/day, 7 days) stimulated healing by re-epithelization and granulation tissue formation.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/19916792

Effect of biostimulation on healing of bone defects in diabetic rats.

Akyol UK1, Güngörmüş M. - Photomed Laser Surg. 2010 Jun;28(3):411-6. doi: 10.1089/pho.2008.2478. ()
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Intro: The aim of this study was to investigate the effects of biostimulation on healing of bone defects in diabetic rats.

Background: The aim of this study was to investigate the effects of biostimulation on healing of bone defects in diabetic rats.

Abstract: Abstract BACKGROUND AND OBJECTIVE: The aim of this study was to investigate the effects of biostimulation on healing of bone defects in diabetic rats. STUDY DESIGN/MATERIAL AND METHODS: Twenty-eight Wistar rats weighting 250 to 300 g were used for this study. Diabetes was chemically induced with streptozotocin, and 14 nondiabetic and 14 diabetic rats were included in the study. The distal epiphysis of the right and left femurs of the diabetic rats were perforated with a surgical bone drill. This surgical procedure was performed on the left femurs of normal rats too. The wound on the right side of each diabetic rat received laser stimulation. The left femur of each nondiabetic (normal) rat served as a control. The rats were assigned to three experimental groups: (1) normal bur (control group); (2) diabetic bur; (3) diabetic bur + biostimulation. RESULTS: There was a significant difference among all groups in substantia spongiosa formation on day 10. According to the Mann-Whitney U test, there was a difference between Groups 1 and 2. A significant difference was noted between Groups 2 and 3 as well as between Groups 1 and 3 and between Groups 2 and 3 in union at 20 d of healing. CONCLUSIONS: Substantia spongiosa formation was slightly more evident in Groups 1 and 3 than in Group 2. Also, there was more union in Group 3 than in the other groups on day 20. As a result, it can be concluded that low-level laser therapy (808 nm laser at 10 J/cm(2)) can have a beneficial effect on spongiosa in diabetic bone repair when five treatments are administered with 2 d intervals between treatments.

Methods: Twenty-eight Wistar rats weighting 250 to 300 g were used for this study. Diabetes was chemically induced with streptozotocin, and 14 nondiabetic and 14 diabetic rats were included in the study. The distal epiphysis of the right and left femurs of the diabetic rats were perforated with a surgical bone drill. This surgical procedure was performed on the left femurs of normal rats too. The wound on the right side of each diabetic rat received laser stimulation. The left femur of each nondiabetic (normal) rat served as a control. The rats were assigned to three experimental groups: (1) normal bur (control group); (2) diabetic bur; (3) diabetic bur + biostimulation.

Results: There was a significant difference among all groups in substantia spongiosa formation on day 10. According to the Mann-Whitney U test, there was a difference between Groups 1 and 2. A significant difference was noted between Groups 2 and 3 as well as between Groups 1 and 3 and between Groups 2 and 3 in union at 20 d of healing.

Conclusions: Substantia spongiosa formation was slightly more evident in Groups 1 and 3 than in Group 2. Also, there was more union in Group 3 than in the other groups on day 20. As a result, it can be concluded that low-level laser therapy (808 nm laser at 10 J/cm(2)) can have a beneficial effect on spongiosa in diabetic bone repair when five treatments are administered with 2 d intervals between treatments.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/19860570

Influence of the use of laser phototherapy (lambda660 or 790 nm) on the survival of cutaneous flaps on diabetic rats.

Santos NR1, dos Santos JN, dos Reis JA Jr, Oliveira PC, de Sousa AP, de Carvalho CM, Soares LG, Marques AM, Pinheiro AL. - Photomed Laser Surg. 2010 Aug;28(4):483-8. doi: 10.1089/pho.2009.2500. ()
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Intro: The aim of this study was to assess and compare the effects of laser phototherapy (LPT) on cutaneous flaps on diabetic rats.

Background: The aim of this study was to assess and compare the effects of laser phototherapy (LPT) on cutaneous flaps on diabetic rats.

Abstract: Abstract OBJECTIVE: The aim of this study was to assess and compare the effects of laser phototherapy (LPT) on cutaneous flaps on diabetic rats. BACKGROUND: Diabetes mellitus is characterized by high blood glucose levels. Its main complications are delayed wound healing, an impaired blood supply, and a decrease in collagen production. Cutaneous flaps are routinely used in several surgical procedures, and most failures are related to poor blood supply. LPT has been studied using several healing models. ANIMALS AND METHODS: Twelve Wistar rats were randomized into three groups: group 1 (G1; diabetic animals without treatment), group 2 (G2; diabetic animals irradiated with lambda680 nm), and group 3 (G3; diabetic animals irradiated with lambda790 nm). Diabetes was induced with streptozotocin. A 2- x 8-cm cutaneous flap was raised on the dorsum of each animal, and a plastic sheet was introduced between the flap and the bed to cause poor blood supply. Nonirradiated animals acted as controls. The dose per session was 40 J/cm(2). Laser light was applied transcutaneously and fractioned on 16 contact points at the wound margins (16 x 2.5 J/cm(2)). Animal death occurred on day 8 after surgery. Specimens were taken, processed, cut, stained with eosin (HE) and sirius red, and underwent histological analysis. RESULTS: It is shown that accute inflammation was mostly discrete for G3. Chronic inflammation was more evident for G2. Fibroblast number was higher for G3. Angiogenesis was more evident for G3. Necrosis was more evident for G2. Statistical analysis among all groups showed significant differences (p = 0.04) on the level of acute inflammation between G1 and G3, tissue necrosis between G1 and G2 (p = 0.03), chronic inflammation between (p = 0.04), fibroblastic proliferation between G2 and G3 (p = 0.05), and neovascularization between G2 and G3 (p = 0.04). CONCLUSION: LPT was effective in increasing angiogenesis as seen on irradiated subjects and was more pronounced when IR laser light was used.

Methods: Diabetes mellitus is characterized by high blood glucose levels. Its main complications are delayed wound healing, an impaired blood supply, and a decrease in collagen production. Cutaneous flaps are routinely used in several surgical procedures, and most failures are related to poor blood supply. LPT has been studied using several healing models.

Results: Twelve Wistar rats were randomized into three groups: group 1 (G1; diabetic animals without treatment), group 2 (G2; diabetic animals irradiated with lambda680 nm), and group 3 (G3; diabetic animals irradiated with lambda790 nm). Diabetes was induced with streptozotocin. A 2- x 8-cm cutaneous flap was raised on the dorsum of each animal, and a plastic sheet was introduced between the flap and the bed to cause poor blood supply. Nonirradiated animals acted as controls. The dose per session was 40 J/cm(2). Laser light was applied transcutaneously and fractioned on 16 contact points at the wound margins (16 x 2.5 J/cm(2)). Animal death occurred on day 8 after surgery. Specimens were taken, processed, cut, stained with eosin (HE) and sirius red, and underwent histological analysis.

Conclusions: It is shown that accute inflammation was mostly discrete for G3. Chronic inflammation was more evident for G2. Fibroblast number was higher for G3. Angiogenesis was more evident for G3. Necrosis was more evident for G2. Statistical analysis among all groups showed significant differences (p = 0.04) on the level of acute inflammation between G1 and G3, tissue necrosis between G1 and G2 (p = 0.03), chronic inflammation between (p = 0.04), fibroblastic proliferation between G2 and G3 (p = 0.05), and neovascularization between G2 and G3 (p = 0.04).

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/19831497

Influence of the use of laser phototherapy (lambda660 or 790 nm) on the survival of cutaneous flaps on diabetic rats.

Santos NR1, dos Santos JN, dos Reis JA Jr, Oliveira PC, de Sousa AP, de Carvalho CM, Soares LG, Marques AM, Pinheiro AL. - Photomed Laser Surg. 2010 Aug;28(4):483-8. doi: 10.1089/pho.2009.2500. ()
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Intro: The aim of this study was to assess and compare the effects of laser phototherapy (LPT) on cutaneous flaps on diabetic rats.

Background: The aim of this study was to assess and compare the effects of laser phototherapy (LPT) on cutaneous flaps on diabetic rats.

Abstract: Abstract OBJECTIVE: The aim of this study was to assess and compare the effects of laser phototherapy (LPT) on cutaneous flaps on diabetic rats. BACKGROUND: Diabetes mellitus is characterized by high blood glucose levels. Its main complications are delayed wound healing, an impaired blood supply, and a decrease in collagen production. Cutaneous flaps are routinely used in several surgical procedures, and most failures are related to poor blood supply. LPT has been studied using several healing models. ANIMALS AND METHODS: Twelve Wistar rats were randomized into three groups: group 1 (G1; diabetic animals without treatment), group 2 (G2; diabetic animals irradiated with lambda680 nm), and group 3 (G3; diabetic animals irradiated with lambda790 nm). Diabetes was induced with streptozotocin. A 2- x 8-cm cutaneous flap was raised on the dorsum of each animal, and a plastic sheet was introduced between the flap and the bed to cause poor blood supply. Nonirradiated animals acted as controls. The dose per session was 40 J/cm(2). Laser light was applied transcutaneously and fractioned on 16 contact points at the wound margins (16 x 2.5 J/cm(2)). Animal death occurred on day 8 after surgery. Specimens were taken, processed, cut, stained with eosin (HE) and sirius red, and underwent histological analysis. RESULTS: It is shown that accute inflammation was mostly discrete for G3. Chronic inflammation was more evident for G2. Fibroblast number was higher for G3. Angiogenesis was more evident for G3. Necrosis was more evident for G2. Statistical analysis among all groups showed significant differences (p = 0.04) on the level of acute inflammation between G1 and G3, tissue necrosis between G1 and G2 (p = 0.03), chronic inflammation between (p = 0.04), fibroblastic proliferation between G2 and G3 (p = 0.05), and neovascularization between G2 and G3 (p = 0.04). CONCLUSION: LPT was effective in increasing angiogenesis as seen on irradiated subjects and was more pronounced when IR laser light was used.

Methods: Diabetes mellitus is characterized by high blood glucose levels. Its main complications are delayed wound healing, an impaired blood supply, and a decrease in collagen production. Cutaneous flaps are routinely used in several surgical procedures, and most failures are related to poor blood supply. LPT has been studied using several healing models.

Results: Twelve Wistar rats were randomized into three groups: group 1 (G1; diabetic animals without treatment), group 2 (G2; diabetic animals irradiated with lambda680 nm), and group 3 (G3; diabetic animals irradiated with lambda790 nm). Diabetes was induced with streptozotocin. A 2- x 8-cm cutaneous flap was raised on the dorsum of each animal, and a plastic sheet was introduced between the flap and the bed to cause poor blood supply. Nonirradiated animals acted as controls. The dose per session was 40 J/cm(2). Laser light was applied transcutaneously and fractioned on 16 contact points at the wound margins (16 x 2.5 J/cm(2)). Animal death occurred on day 8 after surgery. Specimens were taken, processed, cut, stained with eosin (HE) and sirius red, and underwent histological analysis.

Conclusions: It is shown that accute inflammation was mostly discrete for G3. Chronic inflammation was more evident for G2. Fibroblast number was higher for G3. Angiogenesis was more evident for G3. Necrosis was more evident for G2. Statistical analysis among all groups showed significant differences (p = 0.04) on the level of acute inflammation between G1 and G3, tissue necrosis between G1 and G2 (p = 0.03), chronic inflammation between (p = 0.04), fibroblastic proliferation between G2 and G3 (p = 0.05), and neovascularization between G2 and G3 (p = 0.04).

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/19831497

Biophoton detection and low-intensity light therapy: a potential clinical partnership.

Tafur J1, Van Wijk EP, Van Wijk R, Mills PJ. - Photomed Laser Surg. 2010 Feb;28(1):23-30. doi: 10.1089/pho.2008.2373. ()
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Intro: Low-intensity light therapy (LILT) is showing promise in the treatment of a wide variety of medical conditions. Concurrently, our knowledge of LILT mechanisms continues to expand. We are now aware of LILT's potential to induce cellular effects through, for example, accelerated ATP production and the mitigation of oxidative stress. In clinical use, however, it is often difficult to predict patient response to LILT. It appears that cellular reduction/oxidation (redox) state may play a central role in determining sensitivity to LILT and may help explain variability in patient responsiveness. In LILT, conditions associated with elevated reactive oxygen species (ROS) production, e.g. diabetic hyperglycemia, demonstrate increased sensitivity to LILT. Consequently, assessment of tissue redox conditions in vivo may prove helpful in identifying responsive tissues. A noninvasive redox measure may be useful in advancing investigation in LILT and may one day be helpful in better identifying responsive patients. The detection of biophotons, the production of which is associated with cellular redox state and the generation of ROS, represents just such an opportunity. In this review, we will present the case for pursuing further investigation into the potential clinical partnership between biophoton detection and LILT.

Background: Low-intensity light therapy (LILT) is showing promise in the treatment of a wide variety of medical conditions. Concurrently, our knowledge of LILT mechanisms continues to expand. We are now aware of LILT's potential to induce cellular effects through, for example, accelerated ATP production and the mitigation of oxidative stress. In clinical use, however, it is often difficult to predict patient response to LILT. It appears that cellular reduction/oxidation (redox) state may play a central role in determining sensitivity to LILT and may help explain variability in patient responsiveness. In LILT, conditions associated with elevated reactive oxygen species (ROS) production, e.g. diabetic hyperglycemia, demonstrate increased sensitivity to LILT. Consequently, assessment of tissue redox conditions in vivo may prove helpful in identifying responsive tissues. A noninvasive redox measure may be useful in advancing investigation in LILT and may one day be helpful in better identifying responsive patients. The detection of biophotons, the production of which is associated with cellular redox state and the generation of ROS, represents just such an opportunity. In this review, we will present the case for pursuing further investigation into the potential clinical partnership between biophoton detection and LILT.

Abstract: Abstract Low-intensity light therapy (LILT) is showing promise in the treatment of a wide variety of medical conditions. Concurrently, our knowledge of LILT mechanisms continues to expand. We are now aware of LILT's potential to induce cellular effects through, for example, accelerated ATP production and the mitigation of oxidative stress. In clinical use, however, it is often difficult to predict patient response to LILT. It appears that cellular reduction/oxidation (redox) state may play a central role in determining sensitivity to LILT and may help explain variability in patient responsiveness. In LILT, conditions associated with elevated reactive oxygen species (ROS) production, e.g. diabetic hyperglycemia, demonstrate increased sensitivity to LILT. Consequently, assessment of tissue redox conditions in vivo may prove helpful in identifying responsive tissues. A noninvasive redox measure may be useful in advancing investigation in LILT and may one day be helpful in better identifying responsive patients. The detection of biophotons, the production of which is associated with cellular redox state and the generation of ROS, represents just such an opportunity. In this review, we will present the case for pursuing further investigation into the potential clinical partnership between biophoton detection and LILT.

Original Source: http://www.ncbi.nlm.nih.gov/pubmed/19754267

The effect of low-level laser therapy on healing of skin incisions made using a diode laser in diabetic rats.

Akyol U1, Güngörmüş M. - Photomed Laser Surg. 2010 Feb;28(1):51-5. doi: 10.1089/pho.2008.2425. ()
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Intro: To investigate the effect of low-level laser therapy (LLLT) on healing of skin incisions made using a diode laser in diabetic rats.

Background: To investigate the effect of low-level laser therapy (LLLT) on healing of skin incisions made using a diode laser in diabetic rats.

Abstract: Abstract BACKGROUND AND OBJECTIVE: To investigate the effect of low-level laser therapy (LLLT) on healing of skin incisions made using a diode laser in diabetic rats. MATERIAL AND METHODS: Eighteen diabetic Wistar rats were used for this study. One incision was performed on the left side of the dorsum using a diode laser, and the other two incisions were made with a scalpel and diode laser on the right side of each rat. The wound on the left side of each rat received laser stimulation (10 J/cm(2)). The rats were assigned to three experimental groups. Group 1, scalpel (n = 18); Group 2, diode (n = 18); Group 3, diode + biostimulation (n = 18). RESULTS: Reepithelialization was fastest in Group 2 than Group 1 at day 10. The difference between Groups 1 and 3 was also statistically significant in reepithelialization at day 10. There was a significant difference between Groups 1 and 2 and between Groups 2 and 3 in inflammation at day 10. There was no difference between any of the groups in inflammation and reepithelialization at day 20. CONCLUSIONS: Scalpel incisions heal more slowly than diode and diode + biostimulation incisions in diabetic rats. We can suggest that diode + biostimulation may produce the least amount of tissue injury, with the fastest resolution of inflammatory response in diabetic rats. Diode laser incision (4 W) with 10-J/cm(2) LLLT seems to have a beneficial effect on skin incisions in diabetic rats.

Methods: Eighteen diabetic Wistar rats were used for this study. One incision was performed on the left side of the dorsum usin